I believe in moving out of the left lane to let people pass.
But if I got a ticket simply for driving in the left lane, I’d probably fight it, and my argument would be that the left lane was the safest lane to drive in, and the law shouldn’t require me to put myself at unnecessary risk.
So long as I move over when faster cars are approaching, I’m not hurting anybody by driving on the left. But the left lane allows me to bail out onto the shoulder, away from traffic, if there is an emergency (could be an animal darting, something dropped from another car, a blowout, or any number of other things).
Have you ever driven on the Autobahn? If so, then you would understand why.