In real baseball it isn't that bad, because his D is good and he still has a decent obp because he takes walks..... For FB though, these cold streaks are deadly. He's always been a streaky guy in the minors. He's sitting more now and doing a lot of cage and video work to tweak his swing. He's the hitting coaches major project right now.
Some guys are streaky forever, some guys with experience learn to adjust and get out of cold streaks fast when they start. The fact that he has such a good eye for walks even when he's cold makes me think he's got the smarts and instincts to learn how to adjust his swing eventually. It can take years sometimes though, sometimes a few weeks. Even now though, when he's hot, he can carry a team, and when he's cold, he still gives good glove and takes walks... It's that Molina is also good with the glove and is on a mini streak being the main reason for sitting so much.