I think you are wrong. A draft is great for the NFL and any sport (that is why all the major sports do it).
First, it helps create parity which helps keep the popularity. With no draft, a lot of the best talent will not want to go to the worst teams. One of the biggest agendas a rookie has early in his career is to show his talent to cash in on his first free agent contract. If you are a WR, would you want to go to a team with no QB? If you are a QB, would you want to go to a team where the coach is on the hotseat and after learning a system for a year or two, you have to learn another one? It will keep bad teams bad forever.
Second, the draft is a huge revenue generator for the league which benefits both the owners and the players. Why do you think Goodell moved the draft to primetime and spreaded it over three days? It is the second most watched event in the NFL after the Super Bowl year after year. By making rookies free agents right off the bat, that would be a huge revenue stream for the NFL lost. Lose-lose for both sides.
Third, it helps to make the NFL a yearlong sport for the fans. Fans read up on the prospects, study mock drafts, watch endless hours of NFL Network and ESPN learning about the prospects and listening to the rumors of who the teams might be interested in (all this generates more revenue for the owners and players). Many fans have draft parties that rival Super Bowl parties. By just having a draft free agency, it would be like the regular free agency where there will be a lot of interest for a very short period of time, but no event to tie it to and after the top players signed players getting signed in dribs and drabs over the course of a few months.
The draft is a huge part of what the NFL is and it would be hurt if it went away.
I don't really see the draft as being a major driver in the NFL's parity. The draft has been around since the 30's, and has existed during period of greater and lesser parity in the NFL. Baseball has a draft, and is everyone's go-to example of a sport that lacks parity.
The NFL's degree of revenue sharing and hard salary cap are what set it apart from other American sports, and, I believe, wherein its organizational advantages over other sports lie (as opposed to intrinsic advantages, like being a more complex and interesting sport.) It's the revenue sharing and salary cap that makes it difficult to afford the kind of depth that keeps solid 2nd-tier players on benches rather than filling important gaps in teams trying to build around young talent, and its the revenue sharing that ensures that all the franchises will be able to afford to build their teams, so that losing games, losing fans and losing money don't all become self-perpetuating.
With a meaningful cap in place, the draft has actually become at times harmful to teams its supposed to help. Many teams have been set back for years after being forced to over-invest their resources into a #1 overall pick they can't trade out of. Restructuring the rookie wage scale is only a partial fix at most -- having limited the number of teams an incoming rookie can negotiate with to 1, the NFL is constrained to a salary structure that isn't obviously below that players' market value would be.
Meanwhile, there are numerous benefits to the franchises:
* GMs have greater flexibility to build their teams the way they want to. The randomness in the draft is fair because it inconveniences all teams -- by why inconvenience them unnecessarily? Teams will be able to be built with greater coherency to their GM and coache's vision.
* No more rookie holdouts. No more players unhappy with the coach or system they were drafted into, or frustrated with where they were drafted, and taking it out during in artificially constrained negotiations with their team. Getting signed onto a team before camp suddenly becomes entirely the players' problem, and not any one team's.
* Salaries that better represent the players' true perceived value. A top heavy draft will have top heavy salary distribution, etc.
* No artificial restriction necessary on contract structure. With rookies free to shop around, there no need for minimum and maximum contract lengths and bonus structures. If a player thinks he just needs year to prove himself worth a bigger payday, he can sign the prove-it deal, with one cheap year followed by a sizable roster bonus in the 2nd, the way Stallworth did with us.
As for the talk about the draft as a big money-maker -- sure, but that's not because of the draft structure itself, which is quite boring. People watch the 1st round or two of the draft because it's how they find out what exciting new players their team is going to have next year. If ESPN can pull the kind of ratings it did with "The Decision," then the NFL should be able to kill with an entire day of 60+ Mini-Decisions in a sport far more popular than basketball.
I've never heard a convincing argument why the draft is inherently more television-friendly than any other option, so I'd be very interested if anyone can produce one.
Also, it would cost the owners nothing, yet be seen as a huge concession on their part, and that's always good for negotiations.