It's too late to reboot, especially when they have recast the main X-Men roster with great actors.
I think they need the audience to start to care about the main roster characters again.
My suggestion may be out there, but I wouldn't mind if they went the Indie route with character focus films on Jean, Cyclops, Quicksilver, Storm, and Nightcrawler.
I mentioned it in the main thread, but they should do the Mutant Massacre storyline before moving into the Phoenix storyline. The story needs to be grounded and character driven again, and expand the world. By introducing the Murlocks, Marauders, and have the X-Men spend time in the Murlocks community, understanding their world, along with having character development moments, I think that will help the audience care about the characters again.