Between 2000 and 2014, Activision published 35 different licensed Marvel video games across 19 different platforms. This includes major hits like the Spider-Man movie games, the X-Men Legends and Marvel: Ultimate Alliance series, Spider-Man: Shattered Dimensions, X-Men Origins: Wolverine and Deadpool. So, yeah, I'd say they are a proper video game company.

Well, sure, if your measure for properness is middling games with huge budgets.
Activision's combination of squeezing dry, way past the point of abuse (to the customers as well as the devs), old franchises, shady publishing tactics and litigation as a offensive weapon seems quite improper- often tying it with EA as most evil game company. Capcom has its own slew of problems, and Sega is just sad.

Disney publishing on their own (and handing out games to be made to individual studios) would've been a much nicer scenario if you ask me. Hope they find a good publishing partner.