I can totally understand why it isn't going to Wii U,  but 3DS? The console where the sub-series was birthed? A console which will probably sell more than Wii U and X1 combined? I mean,  Capcom isn't below porting way too powerful games to them 3DS considering they released Street Fighter IV there. This is like Rise of the Tomb Raider all over again, except there isn't a chance it's going to 3DS.

Is it being made with the Panta Rhei engine?

That's not enough of a reason. Resident Evil the MAIN series moved to GameCube after being so succesful on PS1 and despite the fact that PS2 sold MUCH MUCH better than the GameCube. RE4 still went exclusive for many years. This is just how business works, loyality is not in the equation.

Same reason Final Fantasy 7 didn't go to Nintendo 64.

They probably didn't want to be held back by the 3DS, focusing on consoles also means a bigger market.

Wake up, no one would buy it on 3DS if they can have far superior versions

Smash Bros. for Wii U 10 mio. seller confirmed.

Pretty sure the 3DS version would crush the PS4/XB1 sales in Japan there chief. 

The reason is likely more technical. If the 3DS is your baseline, then you're really limited with what you can do with the game on the higher platforms. 

PS3/360 being the baseline makes it easier to scale up to PS4/X1. It's just a better fit that way. 

When Nintendo eventually does launch their Fusion platform perhaps they will get Revalations 2 or (by that time perhaps) 3. 

I'm perfectly OK with that!

Apparently Capcom wasn't happy with the sales on 3DS, so even if Revelations sold more on the 3DS than PS3 and 360 combined they are now probably just aiming for the big install base (is it coming to PS3 and 360?) with novelty, or just want to get some brand strenght on the new consoles PS4 and X1, and you know getting it to the 3DS would compromise the game and yadda yadda, i think it makes sense, they just don't have ''room'' to make a 3DS version