I don't think I have ever heard of any problems with hitchhikers on Loveland or Berthoud pass. You're talking about powder hounds here, who just want a quick ride back to the top to get another lap in. I do it all the time at Bert. Likewise I give rides on either pass all the time. It's just how we roll in the west.
Now, if they don't have outerwear on, skis or snowboards, maybe carrying a gun, yeah I'd just continue driving on up the pass.