If it didnt' have so many booths for peopel to play and gets a tons of hands on then i would say you might have a case.
But EVERYONE got to play this game, and from all the demoes I'm guessing a fair amount of play too. All this talk and praise is from PLAYING the game. Doesn't matter who made the game, they woulnd't be praising a bad game. The game was fun, its a new take on shooters. Why shouldn't it get exposure.
I believe Division was refered to in the OP. Reason Splatoon is getting more talk is because Division doesn't do enough different to not get lost in the other 100 shooters shown off at E3. Simple as that. Splatoon and Sunset overdrive are unique shooters in a giant pool of shooters. Thus they get talked about and hyped up. They are refreshing.