Hyatt Place is my favorite of the lower-end hotels, but this drives me crazy every time I stay at one. Almost all of them have a fridge, but I've yet to find one with a microwave. I just don't understand it - that's just barely better than not having wifi. It's a very basic amenity, with very little upfront (and practically no long-term) cost to the hotel.
Even if there is one downstairs (which there often isn't), there's very few things that ruin a night in more than having to go out, go downstairs, awkwardly interact with staff, and hope your food reheated correctly. And let's face it - at the end of the day, you're often not fully dressed anymore, so add that to the list of tasks you have to do just to use a $40 microwave.
The fact that this thread made the front page of the largest frequent traveler website in the world (with the title "How Could Hyatt NOT Put This in Their Rooms?") should be evidence enough that it's way past time for Hyatt to get these in every room.