I believe because the market isn't saturated with wp7 devices is the reason why the hype isn't there. There's a new low-medium level android device coming out every month, with high-level devices released every couple of months by a few different OEMS's.
So there's always this constant hype with Android.
Weren't the HTC Titan II and the Nokia Lumia 900 released around the same time frame? Then we had the Focus 2, which wasn't really amazing.
Point i'm trying to make is that these phones were released within the same time period, so the hype was there and then faded.
BTW I went into a sprint store with a friend and the rep there asked me what phone I was using and I showed him my HD7 and his reaction was "seriously??, you're using a windows phone". I know sprint only offers 1 windows phone, but still everything is Android and IOS.
I believe I read an article where ATT is having their reps educate the customers about all available options and then letting the customer decide instead of pushing them towards a particular phone.
Then again ATT does have a wide range of powerful devices from every OS
::rant::