So 1 rotten apple spoils the bunch huh. And people wonder why the Patriots fanbase is hated lol
I mean, people hated the Heat in the early 2010s pretty much exclusively because of Lebron. Popular opinion recently began to root against the Warriors in large part of Kevin Durant's move there. It wouldn't be difficult to make a case that much of the dislike that exists for the Cowboys is largely due to Jerry Jones. So...yes, one person can make an organization immensely more hate-able.
The only difference is that those people were just viewed as acting "cowardly" or being generally annoying. Kroenke single handily screwed over a city's economy, destroyed the financial well being of dozens of families, and his actions ultimately led to someone committing suicide. I don't think it's unreasonable to dislike a team for that line of logic.