As for why teams pay the big money to rookies that you asked later. Once the system starts there really is no way out without an executive change. One team can't try to change it themselves, they would loose talent, loose competitiveness, then loose revenue.
Do you really think rookies are
overpaid? Are you suggesting that every team then overpays their rookies, otherwise they would be at a competitive disadvantage? If a team chose to spend its money on veterans at bargain deals, and not overpay for rookies, they'd be at a competitive disadvantage? You've got it all backwards. Consider: Would the Dolphins trade the #1 pick for the #10 pick? The #10 pick costs a lot less, and you seem to think that the top pick is being overpaid. If the team with the #10 pick offered it up to Miami, why wouldn't they accept?
I believe most top 10 pick players are overpaid for their performance for the first couple of years. Some mature into their contracts, others never do, and are to expensive and too much of a PR hit to cut.Beyond top 10 or 15 or so, no, I don't think it's an issue, the contracts come down to earth and teams aren't giving millions to someone who has never set foot on a pro football field.
Would the dolphins trade #1 for #10 straight up? No, because it would be a PR nightmare. Not picking anyone would be worse then making the wrong pick. Do I think some team maybe like the dolphins would be better off doing that and saving the money some years? HECK YES I do. I think the dolphins know they are going to be stuck overpaying a player this year, that's why they want to get out of the pick. I also think every team in the league knows they will be overpaying, so no one wants to give them the perceived value to jump up there. At that point you can't reach on a player you want because you have to pay them too much money, you become stuck paying someone superstar money no matter if you think they will become one or not.
And actually the more I think about this, the more ridiculous and un-American it is because those #1 picks don't get paid based off their performance, they get paid based on what was given out last year. Even if this was the worst draft class in history, and the best player in the draft is only as skilled as the player drafted #33 last year, this #1 player is going to get a contract based on the position picked, not his skill relative to the rest of the league at all.