I had a printer heat laminate all of the autographs I got on loose paper when I was a kid. I wanted to preserve them but be able to handle them and show them off too. I don't see it as a big deal and if there is a signature of unquestionable authenticity that I want that 'the market' wants to mark way down for laminating, great, I'm there.
Johnny Carson:
Ray Bolger:
Cheech and Chong:

Gene Hackman:
Ricardo Montalban: