In this case why do they release it for WiiU? Is not that it has a huge user base. It's a good reason, but I think there should be more to don't release it there. A MT multiplatform would be very cheap for them, and would have meant to get some benefit from Sony. Maybe they have some deal for portables with Nintendo, or bad relationship with Sony?
I think both have a very low install base, so I think it isn't the only reason about not releasing it on Vita. Historically Capcom never gave a shit about lower installbase, they supported had several systems with lower install base.