The discomfort you are feeling seeing Sam Elliot before his Cowboy 'Tache can be explained by the Urban Dictionary.
(If you really want some freakiness, find a picture of Patrick Stewart with a full(ish) head of hair.)
https://www.urbandictionary.com/define.php?term=Riker%27s%20Beard
Urban Dictionary: Riker's Beard
Euphemism for a moment in time (typically in pop culture) where something or someone that was lackluster and/or underachieving suddenly and surprisingly became much better and exciting. Taken from Star Trek - The Next Generation, which many fans considered wanting until Commander Riker grew a beard at the start of Season Two, after which the show was solid and well-received for the rest of its run.