Politics: Which do you think is the motivating ideology behind the NFL not hiring Kaepernick, patriotism, or capitalism?

Money.

If it was patriotism they would have fired him the first time he took a knee and paid off his contract. Instead they waited and just chose not to renew his contract. No other teams are clamoring for his services because he isn't a "team" player. No employer wants their employees turning their job into a soapbox for their political views because businesses want EVERYBODY's money.

He is at best an average good to fair player, the league will excuse almost any conduct and crimes if a player is elite, but when they are not great then there is a different standard on conduct. Besides he is not a starting quarterback and back ups don't make the money he was making before his talent went away. So if he had the talent they would over look his taking a knee but since he doesn't the teams are not willing to suffer the grief and risk the ill feelings of the paying fans.

Kaepernick did something insulting to America as a nation.

The "NFL" doesn't hire anyone. Teams do.

And he's actually not all that great - he's more of a political star than a football one.

Given in a Trump universe, all publicity is good publicity, no team is avoiding him because of conflict.

He's like Tim Tebow, who was similarly controversial. They didn't last long because they weren't very good.

NFL is corrupt, team owners are corrupt rich assholes

from the viewpoint of an owner, he looks like trouble on the team in the making. Thus, not a lot of interest in hiring him.