If you look at the past few updates, does it not look like they have been considering the "majority" of people's feedbacks? Keyword is majority. If there are not enough people requesting for a certain feature, we should understand on why it wouldn't be implemented or delayed till later on.
You talk about things like restrictions on seasonals, inviting people to online rooms, and whatever it is you're talking about things in GT4 not making it to GT5. The last time I checked, there are a few (minority) of people that have requested the things you mentioned above. If you look at the GT5 feedback, those things are not even close to what's on the top priority for the "majority" of the fans. Things like weather, visual/mechanical damage, and other things that were high on people's priority list (like in-race game saves) made it. You'd also see people tweeting on his twitter page, and a lot of times, Kaz himself would respond back, even through an update patch.
The last time they had restictions on seasonals, people complained. When there aren't people still complained. Do you really think everything it's that simple to satisfy everyone?
No they don't respond to every feedback, but I can say for sure they have for a lot of things. The problem with a lot of people is that just because something they want doesn't happen, they assume they're not listening or even considering it. I'll tell you that that's now how life works... at least for me.