Re: Why do people hate the S5?
One thing I saw sort of touched on but not really expanded is simple.
Samsung used the Galaxy S line to really push boundries hardware-wise. It was the cream of the crop, top-notch stuff. This has forced other companies to push hard to stay caught up. Now we're at a place where spec-wise, flagship phones have pretty much hit par, meaning apart from a specific spec (say camera megapixels) as a package specs are pretty much the same across the board. Also, hardware isn't evolving as fast as it used to, meaning there's not as much "WOW" factor from 2013 models to 2014 models (again, iPhone 5 to 5s, or GS4 to GS5). It seems that now the focus is (or should be) on optimizing hardware and software. Apple has been doing it for years. Moto did it amazingly well with the MotoX and MotoG. I think it's high time for other companies to play "catch up" in this area as well. And yes, Samsung could probably make the biggest strides in this area, but LG's skin is pretty heavy too from what I've read.
The only area (hardware wise) that really needs to be improved is battery life. Sadly, this is something where it's out of smartphone maker's hands. Li-Ion batteries have been around forever, and while there're good, they haven't evolved at nearly the same pace as other mobile technology.
So, part of the hate is that Sammy just can't WOW people like they did with the first Galaxy S, the S2, the S3, and to a lesser extent, the S4. Now that the S5 is a slight "evolution" rather then ground-breaking, people are disappointed that a company that once was known for being cutting edge, is now seemingly to play it safe. You don't want to push boundries too far, because you'll be alienating your current customer base - which looking at Sammy's sales numbers is fairly significant. There's also the rumored F-series to keep in mind, and the Note series (which seems to be taking over as the "ground-breaking" model instead of the S line) to keep in mind as well.