Indeed, Brawn and his team found a loophole and exploited it, they were not the only one, they just did it better than the few others that did it. Then by the end of the season everyone had one and in part because brawn then had no money to spend, their car wasn't really competing for wins by race 8 of 17.
If we make these sweeping regulation changes you speak of, how long do you really think we'll get wacky races before all the teams converge on the same answer which is what they've done every time anything new pops up.
The manufacturers don't want their engines blowing up, sane people don't want to see a driver smashing in to a wall at 200mph because his brakes failed and nobody could tell him, regardless of how safe the cars are.
I'm all in favour of making the driver decide when to pit, but in murky conditions when we get the joy of seeing some on inters dancing around and some on wets, how would you have the driver communicate that choice to the team with no radio? Because if its one way radio then the drivers asks "should I come in" and the teams will put a board up at a designated corner, or something, to get around it. It's little different to banning team orders. Multi21 and suddenly team orders are still happening (when the driver doesn't act like a dick and ignore his team lol).
What F1 wants to be is exactly what you describe, the pinnacle of engineering know how and technology, right on the cutting edge of everything, pushing to the limit with minimal regulations, and once upon a time that's what the sport WAS because it could be. Money was everywhere and even a big team was nothing compared to what we have today. There are only 3 or 4 teams that can afford to even try in that magic formula today since tobacco sponsorship is gone and even regular sponsorship isn't bringing in the money like it used to. As we know from Indy '05, watching 6 cars trundle round isn't fun for anyone.
Lets not forget that Brawn didn't come up with their magic in their first year on a shoestring budget. It was bought and paid for by Honda before they tucked tail and ran, and I doubt they were running a budget closer to the Force Indias or Williams of the grid at that time, and in fact were nearer the Renaults and Toyotas. With unlimited funds and unlimited resources, with none of the pesky regulation, the likes of Ferrari, Red Bull and Mercedes can test out a multitude of options. What can Williams, or Sauber, or anyone else do?
The sport has changed and evolved from "the good old days" where cars were designed on paper and then tested to death on track and in the tunnel, designed and built by a small team where one mustachioed pipe smoking genius could simply look at a car, say "add a dangeflangle just there, about that long" and the car goes faster. Even the small teams are still spending bank because its the only way to do it. Do we want to see Merc, Ferrari and Red Bull running magic cars that run 6 seconds faster than everyone else because they have the resources and facilities to investigate every option, test till the sun goes down day after day in this new formula of barely any regulation at all? Where everyone has active suspension, skirts, fans, exotic alloys etc that once everyone has them, are now just expensive addons that don't actually differentiate anyone from anyone else?
I'd love a deregulated formula. Get some sheikh to stump up some crazy money and run a 40 race season with insane cars, engines and drivers that are certifiable for even trying to drive the cars. I'd LOVE that. But since that isn't ever going to happen what can we REALLY do to make F1 more interesting, more appealing and more random?
Find a way for teams to spend money better, rather than just more. Find a way to get cars close together again like "the good old days". Find a way to get more cars on the grid & more engines on the grid.