What is it with rich celebrities getting ridiculously lenient bails that they could easily pay in the blink of an eye?
Because if they got properly-set bail, people (possibly the celebrities themselves) who don't understand how bail is supposed to work would scream about how they aren't being treated equally.
This and most NFL players are able hire a great if not top tier lawyer to be their legal representation in court.
Why are so many NFL players so violent? Is it brain damage?
Entitlement.
Seriously. In a nutshell. This.
Look at all the stories about how the jocks are treated in high school and college and remember that the NFLers are the creme of the crop that actually make the big bucks for people. An entire lifetime of being told you can get away with anything isn't going to end well.
The poetic justice that goes with players like that is the fact that an NFL career lasts usually 3 to 4 seasons for typical players because playing football is so taxing on the body, and the NFL gets a new talent pool coming in every year. Being a "problem child" to the team can also help shorten a player's career. Better or more popular players can play for about 5 to 8 seasons. Only exceptionally gifted players and/or players who miraculously haven't gotten seriously injured last 10 or a few more seasons.
Once those people stop playing for the NFL, the lucrative paychecks stop as well. It isn't uncommon for many NFL athletes, regardless of how many seasons they have played, to go broke. A quick Google search will show you numerous stories and sad statistics about how many players go broke and why. Heck, it isn't unheard of that broke NFL players will sell their Superbowl ring because they're in debt.