Analysis: Hey, It's That Guy!
Reasons for the occurrence of this trope.
For instance, if a middle-aged character actor gets a good rep (there is nothing like personal connections in a crowded, cut-throat business like the Hollywood acting pool), he can appear in numerous movies and TV shows each year. Ronny Cox is a good example among actors always available as white male authority figures, Lou Gossett as black male establishment types of any social class, Mako in any middle-aged male role requiring an Asian (when he was alive, that is), and Tim Curry
as any evil, bearded
bloke who dies in the end.
They never get the lead but that's often best for them. That means that nobody ever blames them if a movie bombs and they never become unaffordable. It means that they'll never grab the headlines or grab your attention but they'll grab the paycheck at the end of the day.
Another excellent category for this is dwarfs: there are only so many good, trained adult actors just over three feet tall and even fewer with the connections to constantly get speaking parts. Most long time movie and television fans will recognize a half-dozen familiar faces on small bodies: Billy Barty, who played these roles from the 1930s to the 1990s (180 entries just in the IMDB, beginning at age five), Billy Curtis (High Plains Drifter
), Warwick Davis
, the Leprechaun
and Harry Potter
films, and Prince Caspian
), Peter Dinklage (also Prince Caspian
, Game of Thrones
) the great Michael Dunn (Ship of Fools
and The Wild Wild West
), and Danny Woodburn (Mickey Abbott on Seinfeld
, Big Figure in the Watchmen