Originally Posted by SuperT
Thor or Iron Man (or even Captain America to some degree) weren't particularly A-list until Marvel just took the leap and made their movie's either.
Plus, X-Force is one the more popular X-Men teams from the comics, especially the incarnation with Cable as the leader. Fox is going to have to take the leap at some point and start making more movies other than X-Men proper.
X-Force is a good start.
Captain America, Iron Man and Thor were at least used in the cartoons and videogames. And before Captain America came out in film, I've seen shows used his name as a reference just like with Hulk.
And X-Force is coming from FOX and not Disney, I'm pretty sure FOX will market this as another X-Men spin-off and I'm not afraid some people will just see this as "X-Men light" or another mutant team with a different name.