It literally takes years (really, over a decade) for a fan to final land season tix. Meanwhile someone "lucked" into them and use them - as if they're entitled - to make a lot of money. There's an implicit understanding that a season ticket is a fan who wants to watch their team. The season ticket holder that sells all or most of the seats is just being exploitive.
It does hurt the team - but it's not because the team wants a cut of the resale. A "fan" season ticket holder is a real asset to the team. They're more likely to buy merchandise, for example. A "investor" season ticket holder helps no one other than themselves.
I think the only reasonable alternative for the Broncos would be to raise prices to the level they're being resold for. That can easily be monitored and it would destroy the exploitive advantage. It would literally be the fair thing to do. Hmmm, how would that play if a team jacked prices? It is the team's right to get fair market value; not the exploiters.
Also, having actual fans own season tickets would reduce the number of opposing team jerseys in the stands. A team has a legitimate right to enhance the home field advantage.
So, my answer is that I not only think the Broncos are within their rights, but that it's actually the right thing to do. I applaud any team that has put themselves in a position to have a multi year waiting list to put fans and team first over exploitation.
Go Cornell Big Red - County Kilkenny - Go Cats!