Some silly, campy, kids entertainment franchises have never gone out of the public eye. Batman has always been around in print and has kept showing up on TV and in the movies. He doesn't have to be revived, just restyled, because he has never been away. But the Lone Ranger just stopped dead circa 1960. You want to relaunch him now, you have to use jump leads. Only us whiskery old grand-dads remember him as a living force and not necessarily with any great fondness. If you're putting a lot of money into him now, be warned; you're effectively starting from scratch.
And that's why the movie slumped. It's got nothing to do with the critics.
PS. I quite like Johnny Depp, but he can't ensure profits just by turning up. I don't believe any movie star can these days.