I am not really sure what you are talking about when you say "hardcore gamers" given these criticisms. Given what the Wii U offers with asymmetrical gaming options, Miiverse integration, retaining of motion control options, and a new interface for gaming, and a jump to HD graphics, I would say Nintendo is supporting their "hardcore" base extremely well. The only times when they haven't done the best job is with the N64 and GameCube. On all other major systems (handhelds included) they have done an outstanding job.
If you are talking the type of "hardcore gamer" that live on playing shooter games 12 hours a day, don't work, and don't really have a social life - then I think Nintendo has opened up options for them given the new controller interface abilities - such as interactive stat tracking on the bottom screen while the action occurs on the top screen; but whether you can tear these guys out of their computer seats is another question. I don't think it is in the best interest of Nintendo's fanbase to focus on these gamers; and as Nintendo, their fanbase is the largest videogame related fanbase in the video gaming industry.
I describe myself as a little dose of toxic masculinity.