They didn't appear because they don't have a big fan base? Did you even SEE the cast of X-Men First Class?
She was front and center in the books when the movies started...and Cyclops was actually dead at the time.
Do you even read the comics? 1 or 2 books center on Cyclops at any given time (and there are even 2 of them now)...the franchise hardly revolves around him...compared to the dozen or so that feature Wolverine at any given time and even the massive event they're making out of his death and the aftermath (and you can bet he'll continue appearing in the books the whole time he's "dead").
The problem isn't just the amount of screen time in the movies...it's the character's treatment...Cyclops was trivialized in the movies the whole time only to get killed off in the most insulting way possible...I actually would have preferred he never appear in the movies at all to what they did with him there.