Selfish implies a complete lack of interest in others. Here, he could reasonably say that " I value an extra year with my teammates at $2 million dollars" and still have good reason to walk away. Playing college sports was the best experience of my life. But I wouldn't risk millions of dollars to do it*. I don't think that's selfish (literally or in the common parlance). It's just rational decision making..
This is just not true. In no way is it rational, it's a completely ignorant way to approach your draft stock/future as a player.
I hate debating semantics on the internet, but sitting out a year of college to be fresh for the league
is selfish. It's an exclusively self-interested act which is the definition of selfish. From Merriam:
concerned excessively or exclusively with oneself : seeking or concentrating on one's own advantage, pleasure, or well-being without regard for others
You're putting your well-being ahead of any interest in team. This isn't even debatable, and this reflects REALLY poorly on your motivations as a potential draft pick. In fact, the personnel guru for the 49ers/Seahawks who just came over to the Redskins was talking about this the other day in his introductory press conference. He said specifically that one of the things they put emphasis on over height/weight/speed is intrinsic motivation, character, and desire to win. He said it's more important to have hungry, team-first guys who will do anything to win for the team than the biggest/fastest/strongest who only care about themselves. These are direct quotes from a top personnel guy less than a week ago.
Anyone who says "I'm not playing this year to save my body for the NFL" is implicitly saying "I'm not playing because I don't care about winning or this team relative to my own financial gain." That will KILL your draft stock and the attempt to protect your future/money will instead cost you millions upon millions upfront... and then you'll be rolling the dice anyways in the NFL that you don't get hurt in not just 1 season but in 3 straight so you can get to the second contract.
It's common sense and why no one has ever done it. The only people who have even tried something similar to getting out "early" are Mike Williams and Maurice Clarett failing in the same year, and that was a very unique situation.