College coaches are not amateurs. Why wouldn't they be paid? As for what they ARE paid? I'm not arguing that head coaches at big programs make way too much money but just to put it in perspective your average head coach probably put in decades as a Grad Assistant coach, Positions Coach and Coordinator before they hit the Head Coaching jackpot.
I've got a college friend named Steve Spagnuolo who went into coaching and ended up as an NFL head coach making millions but for close to 30 years he worked his ass off in some very low prestige jobs making diddly for money.
Massachusetts
(Graduate Assistant)
Washington Redskins
(Player Personnel Intern)
Lafayette
(Def. Line/Special Teams Coach)
Connecticut
(Defensive Backs Coach)
Connecticut
(Def. Coordinator/DB Coach)
Barcelona Dragons
(Def. Line/Special Teams Coach)
Maine
(Defensive Backs Coach)
Maine
(Def. Coordinator/LB Coach)
Rutgers University
(Defensive Backs Coach)
Bowling Green University
(Defensive Backs Coach)
Frankfurt Galaxy
(Def. Coordinator/LB Coach)
Philadelphia Eagles
(Defensive Assistant)
Philadelphia Eagles
(Defensive Backs Coach)
Philadelphia Eagles
(Linebackers coach)
New York Giants
(Defensive Coordinator)
St. Louis Rams
(Head Coach)
That's pretty common for football coaches. It's a transitory life that's hell on your family life. Another of my college friends who became a coach is on marriage #6. Trust me, coaching has it's up side but it's also got some MAJOR drawbacks!