Why won't this topic ever end? Let's clear this up:
If you've noticed, virtually every asian market variant of every phone from almost every manufacturer typically has a removable battery and an SD slot. Even the modern versions of everything stays the same - HTC One, HTC Buttery S, G2, S4 (more internal storage + microSD), etc. The list goes on and on. Some people cry 'favoritism!' because sometimes the OEM comes from that area. No, that's not it. The reason is simple: average customer market needs (the largest group of consumers).
Despite what many people believe, American consumers as a whole (the larger group) do not purchase memory cards for smartphones and when they do they are typically the 16gb or 32gb variant at the most. Americans as a whole do not even typically purchase the phone option that has more than 16gb. Don't believe me? Go pull up sales numbers of every phone from the past decade that had 2 or more variants and see which one sold the best. The answer is simple: the cheaper, smaller sized one. This even applies to the iPhone. Virtually no one buys the 32gb and the 64gb is even more rare. The iPad follows the same suit, the S4, Note... I think you get the point. This also applies to removable batteries. The average consumer in America DOES NOT purchase an extra battery. In fact, according to accessory numbers, the only accessories Americans as a whole purchase is typically a car charger and MAYBE a case and rarely anything more than that. Remember: we're talking about the average consumer. Most of us here are typically not always average consumers. How do I know that? Simple: The average consumer also doesn't frequent tech sites like these. They follow trends, watch commercials and make a decision solely off of what is 'cool' and the only decision they make is which 'group of cool' they want to fit into.
Why no removable batteries in America
So, getting back to the topic at hand (why no microSD or removable batteries in America) we see an easy decision for OEM's when it comes to American consumers. Why add removable batteries when hardly anyone buys them? Some may argue that they would do it just to be 'convenient', but then you forget what American consumers value the most in a smartphone: looks. Yes, we're vain people. Apple proves this successfully in virtually everything they make. Americans - as a group (and this is statistically proven) - are vain. Almost everything we buy has 'looks' at the top of the list. The simple fact is that you can make a much nicer looking product that does not have a removable battery. Other advantages include avoiding problems associated with faulty battery units (a built in battery is quite different in technology than a removable one) or dealing with supply chain issues and such. Plus, it's one less thing for the consumer to tinker with and mess up in some way (often times the few people that do buy extra batteries RARELY get an OEM one - causing problems).
Why no microSD
Similar to removable batteries, microSD cards do statistically cause more problems than they solve. OEM's do not test performance based on the hundreds of thousands of different variations of memory cards. They test it based on the internal storage, which again - similar to removable batteries - has different technology slightly than what a removable card has. The hardware associated with internal flash is different in some key aspects than a microSD and yes, STATISTICALLY, internal memory has crashed significantly less than microSD.
But, this is not the main reason they don't do memory cards. It often times again goes back to design. Removing the hardware associated with a microSD frees up a little space for other things. See where I'm going with this? Design again. It's one less thing that can go wrong and gives them one more option of something else they could tweak. Plus, as aforementioned, Americans as a whole do not purchase memory cards like you think they do for smartphones. Most people get by just fine with their 8-16gb phones - otherwise they wouldn't be buying them.
Why do asian market typically get microSD and removable battery variants?
Because their average consumer market needs actually has proved that they need and USE them. If you've taken a look at the asian market, they actually use their phones - compared to Americans which "think" they do. The main difference is many of these markets is that because of financial woes often times people buying a smartphone likely made the decision to buy that instead of a computer entirely. They don't have a laptop. They don't have a tablet, they don't have a desktop. They have a smartphone. As such, their needs greatly dictate needing removable batteries because they will obliterate their battery life in a few hours (ever notice that most asian market variants already include 2 batteries...do you really think the OEM's just do that to be nice? No, it's NEEDED. People wouldn't buy it there if it didn't have it). They need microSD because once you start getting above 16gb for internal flash storage, it gets expensive in those markets. Memory cards are cheaper for the consumer. A phone with 32gb or 64gb internal would be lusted after, but the cost is high and it's better for the OEM to just release a 16 and 32gb version with memory card support.
Even in America you'll notice few Android OEM's have tried to release a 64gb variant. While most of that has to do with the fact that it won't sell more than a few hundred thousand units at best, it's also because it's expensive. Apple is pretty much the only consistent player in this segment and look at how expensive that phone is and the 64gb barely sells, but they can afford to do that.
.... are we done with this topic now?
As a side note
Yes, there is some truth in carriers wanting you to use memory cards because accessory sales are nothing but pure profit. However, go pull up sales figures on how well memory cards sell in stores and you'll see it's poor. So, obviously it's not a big enough factor to force them to make OEM's release microSD support...at least in America. The real truth is that carriers want you to use their network. Data is the new money maker...not microSD. The more data you use, the higher your plan needs to be. Carriers have more reason to encourage you to use data than they do to encourage you to buy a microSD. A microSD is just a one time sale. Data is monthly and if you're on contract, they make a lot more money from you signing up for a higher tier data plan they do the megabyte plans.
If you haven't already gotten on board with internal flash and still think microSD is the future you're going to be very depressed come 2015. In 2014 you'll see that most companies will already by then be releasing smartphones without microSD and then by 2015 virtually no one will - in America. Data is in, microSD is out. Apple and Google won so get with it. Frankly, it's better this way (performance wise), but many people don't see it yet.