Unfortunately, it's a necessary evil. These guys have a relatively narrow window to make enough money to set their families straight for the next few generations if managed correctly. Also, the NFL, unlike any of the other leagues, do not guarantee much money. Being that it is the most inherently dangerous, you'd think they would, but it's not that way. NBA money is guaranteed (the NY Knicks were still paying both Allan Houston and Larry Johnson well after a decade after they last played for them.). MLB money is guaranteed (The NY Mets are STILL TODAY paying Bobby Bonilla and he hasn't played for them since the turn of the 21st century)...So in that sense, the football players have to maximize their earning potential while they're healthy enough to be deemed worthy of the money teams are willing to offer.
And even more unfortunate is the fact that the fans typically only see the player "not honoring his contract". Most of the outrageous NFL contract numbers you see are backloaded, meaning that in a simple example, the payments would be paid out in increasing increments. Of course on the back end of the deal, the player is older and probably more likely to have gotten injured, then the team can just cut him and not pay what THEY agreed to. A prime example of that is Hines Ward & the Pittsburgh Steelers (I personally hold both parties in very high esteem). Ward held out near the end of his career and the fan backlash was ridiculous. Steelers fans are some of the most loyal in all of sports. But not many of them batted an eye when Ward was pretty much rendered useless as a player (outside of being a mentor for younger receivers), but still owed big money on his contract but was cut and pretty much forced into retirement.
So it's a business. As is college athletics whether we wanna believe it or not. It always has been. There are just more vehicles now for college players and former college players to have their voices heard. I certainly don't want this to turn into an NCAA should pay players thread. We have about 20 of those already.
On the point about the RB position being phased out, I'm with you, as this troubles me a great deal. The same as it troubles me that the traditional 7 foot center and traditional low post power forward in the NBA is being phased out with the infusion of rules to favor a more Euro style of play (wing player dominant). It is bothersome, but it doesn't keep me from watching it. Although I know that both of those developments are centered around money. More scoring in football, More movement in basketball, means more fringe fans. The hardcore fans still get SOME of what they want and if they're hardcore fans, they'll watch anyway. I imagine that's their thinking.
And tying that back into the original point, running backs especially won't be getting paid. The Seahawks paid Shaun Alexander a boat load of money after he had produced. And unfortunately (see a theme with that word?), Shaun got dinged up after the big money. Along with him trying to rush back from a broken foot, the departure of Steve Hutchinson, and the aging of Walter Jones, he was never the same. So no running back will probably ever be paid big money again after age 28.