Q:

Why wasn't Gambit included in the X-Men Cinematic Universe?

I am currently re-watching the X-Men animated series of 1992. As I remembered, there is no special focus on any specific X-Men character in the series. The X-Men appearance order in the intro is

Cyclops
Wolverine
Rogue
Storm
Beast
Gambit
Jubilee
Jean Grey
Professor X

Among the X-Men featuring in the intro, Jubilee is given no substantial role in the movies, while Gambit is included only as a side character in X-Men Origins: Wolverine.
Is there any specific reason expressed by the actors, directors, producers or any other relevant person explaining why Gambit was mostly omitted from the X-Men Cinematic Universe?

A:

Gambit has had his own eponymous film in development. This would likely have been his first major appearance, but it's been a troubled production. Prior to that, he had a brief scene in X-Men Origins: Wolverine.

