Very nearly all NFL players serve their football apprenticeship at one college or another. This may or may correlate to becoming educated, or even to being a decent human being, depending on the individual. Some schools are more serious than others in making sure that their hired gladiators get a real education, and some players are certainly more serious than others about becoming educated.
There have always been hoodlums, thugs, and borderline-illiterates who find a way through the system, and once they sign a pro contract and get that big money, some of them exhibit really outrageous behavior. In recent years, with the dollar amounts in play becoming ever higher, a few of these antisocial types have found themselves able to misbehave in extremely high-profile fashion. Lots of these guys are very much in love with themselves, and when they get those fat contracts, they understand them as an affirmation of their high opinions of themsleves. They believe themselves above the rst of us, and don't think that they're subject to the same ruels as the rest of humanity.
On the other hand, there have always been good guys whose participation is sports truly exemplifies all the platitiudes we've all heard about sportsmanship, discipline, etc. I'm not speaking only of the elite group of true "scholar-athletes," guys who have gone on to become Supreme Court Justices*, etc., but also of the many who may not have 98th-percentile IQs and are not especially bookish, but who are decent thoughtful citizens and in many cases donate much of their time and fortune to charities in their communities. The current roster of the New Orleans Saints, for example, seems to have been assembled with an eye to "character" ~ solid citizens to a man, many of them volunteering for varous causes in a community that needs all the help it can get.
I don't think that there are any fewer good guys "recently" than ever before; I think that what's different about recent years is that the bad apples are finding ever more spectacular ways to offend the rest of us.
*(There has been only one US Supreme Court justice with a pro-football background, the late Byron "Whizzer" White. I used the plural because I know of at least one state supreme court justice, Alan Page of Minnesota, formerly of the Vikings and, before that, Notre Dame class of 1967.)