You call it lowering expectations, what he said is probably the reality of the situation. Just like when they hold an update back for older models until the newer one releases, which carriers have done in the past. Doing so might get a few people to upgrade to the newer model, where if they released it prior to the launch, they may just stick with their current device.
Yes Google is a big company, but the only updates they handle is for their Nexus devices. Any non Nexus device update is handled by the OEM & carriers. The reason you don't have those issues with a non carrier Nexus or an iPhone is that they don't go through the carriers for approval, they simply push the updates to their devices. OEMS have to modify Google's update for their device for their skin. And while Motorola appears to be running a stock version of Android, there are some differences. And then there's the carrier's involvement as well. So far, Apple is the only device that carriers are hands off with in terms of updates, due to Apple leveraging their position to make it happen. That's one of the reasons why no one thought Verizon would ever get a Nexus device again, after what happened with the Galaxy Nexus. The only way you're going to get the update experience that you would with a Nexus or iPhone, is to get a Nexus or iPhone, simple as that. Some may surprise us like the Moto X has done recently, but that's the exception that proves the rule. If it's carrier branded, and not an iPhone, chances are you'll be dealing with waiting for updates.