Couple of points:
D1 teams can easily outrecruit any d2 or d3 team.
That's not true. It doesn't happen constantly, but it happens more frequently than you think. D2 teams take players away from D1 teams, and D3 from D2 teams.
It'd make D3 far more interesting. Recruiting a freshman who has great ratings but no potential.
You can do that now. They do exist. They're mostly low-WE guys... who may or may not have potential listed that they'll never fulfill.
It'd also make low D1 more interesting, perhaps signing at top 20 recruit without a lot of potential that no D1 schools want.
Can you show me an example of that kind of recruit? I'm inclined to believe he doesn't really exist, or is extremely rare, but I can't say that with certainty... and I can't prove a negative.