There have been series' like that, but its equally bad, in the other direction. In that scenario drivers qualify in speed order, then they do the race in the same order. It's not much fun to watch.
Every track is the same because all the cars have the same strengths and weaknesses.
In other words, there are too few variables.
Good races are where teams are involved to make the best car, drivers are involved to execute the best driving, strategists are involved to make the best decisions, and luck creates jeopardy for all.
With different cars (any they are remarkably different given the extensive regs) some do well at high speed tracks, others prefer corners and so on.
I mean that's pretty much the IndyCar spec and they have pretty decent racing. They've done things like embracing underbody aero to cut down on dirty air to allow them to follow closer, low downforce specs on ovals to force them to race the track. Even a spec car, a drivers ability to communicate setup issues to the team, the team to implement them, the budget to do it. F1 is some of the best in the world, but none since Mansell have really came over and dominated, not even Alonso.
Current IndyCar is pretty good compared to the IRL years, this isn't an argument to make F1 a spec series. I was IndyCar for close exciting racing, I watch F1 for the engineering battle as well as the drivers. I think for a lot of F1 fans, the off track drama, the development of the teams through out the season, and the cool ideas they come up with to try to push the boundaries are about as good as the on track entertainment.
The spectacle is still very important, there is nothing like seeing F1 cornering speeds in person. IndyCar isn't close, they have their oval thing with ultra high sustained top speeds, but not even close to F1 on a road course. When you see how fast an F1 car can change directions, it genuinely boggles the mind that a human is behind that. And they've really dropped the ball in that aspect this season. The fans aren't happy, the driver's aren't happy. Something needs to change.