TL;DR: The ACIV Wii U port was rushed or mishandled. Problems found in that game aren't found in other multiplatform games.
Being a longtime Nintendo fan, and believing gameplay >>>> graphics, I have rebelled against the "Wii U is too weak" and "Nintendoomed" narrative. Wanting to put my money where my mouth is, I decided to make the Wii U my primary console this gen (as much as I could, anyway, given weak third-party support), added some funds to my Wii U, and bought my first multiplatform game, ACIV.
After playing for about 30 minutes, I was having second thoughts about making it my primary. The analog sticks had HUGE dead zones, so all camera turns are nearly 90 degree turns. This causes severe issues when trying to chase a target who is always 45 degrees to your left or right... The game was also choppy, suffering from a low framerate, which I can stomach, quite honestly, but it did add some credence to people claiming the Wii U was weak.
I could not fathom that Nintendo would release a controller with such huge dead zones on the analog sticks, so I took a risk, and downloaded Need for Speed: Most Wanted. That game has no dead zone in the analog sticks, the framerate is smooth (as far as I can tell), and it looks great. I've had no issues with this game, aside from some stupid EA Origin connection things. This leads me to believe that the ACIV port was handled very poorly by Ubisoft and was either rushed or farmed out.