It's the pinnacle of motorsport in that it's the best drivers in the world competing with some of the best machinery in the world created by some of the best engineers in the world. I'll admit it doesn't always have the best racing action (though if you have the right tools to watch it, there is plenty of great racing to be seen in almost every race) but when you do see great close racing, especially at the front of the grid, the fact that the cars have no common parts other than the tires, makes for a great spectacle IMO.
Spec racing gives a lot more action and it's great for what it is but I'd never sacrifice F1's formula for that. It's what makes F1...F1. That's just me though.