Okay, theoretical, but this may be another contributing factor.
Broncos players constantly talked up as the next big thing. To the point where every week, a commentator will say "keep an eye on X Player, they'll be a superstar", all while the opposition's score ticks over. They're all the Next Big Thing. Who knows where the spruiking comes from, I tend to think it's player managers trying behind the scenes trying to get their players in the headlines for when Contract Time comes around. But whatever.
The point is, those players believe it themselves. They're the Next Big Thing. They think they've already made it and it's just a matter of waiting until next contract time. They don't put in the extra efforts. They just rely on their talents.
Older players meanwhile know what it takes. Even if they never even became Big, they know the effort that has to go in. They tell the young kids to pull their heads in.
Young players won't take that shit. Old players are passed it and sucking the money out of the cap, money these Young Superstars deserve because the media say they're definitely going to be A Big Deal.
Come post game, another big loss. Young players blame the broken old has-beens. They say the right things, that everyone needs to do better, but privately believe that it's not their fault they're losing. They only dropped one ball or let that one try in. It's bevause the rest of the team sucks. They're a superstar, they deserve better. So you end up with these kids that think they deserve the money and the success, who ring up Politis because they're sick of playing for a shit team. All the while, the team is shit because individually they don't think they're part of the problem.