I'm not saying that Demoff is the greatest thing since sliced bread.
But exactly where are all his failures? He runs the FO, not the football team. And by all accounts, it is a well run organization (not the Funny Farm that Georgia had) and the cap is managed very well, and the team has a sterling reputation among agents for playing it fair and straight.
I suppose one could pin Fisher on him, but remembering that the Rams were in St. Louis, and the whispers were that the team was going to be moved, and the team was HORRIBLE, it's not like there were qualified and better people lining up to take the job.
Demoff doesn't make personnel decisions. He doesn't decide on schemes. He never claims to be an X's and O's football guy or talent evaluator.
His job, in this case, is to find the best possible HC to run the team and make the football decisions.
Is he qualified to do that? Probably.
I wish the Rams had hired a true football guy as the team President, and have him do the choosing; and then Kevin would be the COO. But that's clearly not how Kroenke wants it structured. But look around the league; there's no magic formula for success in this regard. Many teams with "football guys" running it pick HCs that fail.
As for the St. Louis thing, to call KD a liar because of how St. Louis went down is emotional, but not pragmatic. Clearly KDs boss was intent on moving to LA (what businessman wouldn't be?), but had Demoff laid his hand on the table and turned up all his cards, he would have been naive or an idiot. And neither Stan nor Demoff is naive or an idiot. Stan more than doubled the worth of the Rams overnight. That's how the game is played.