eh, I think they have a few kernels of truth. But to be clear, those methods teach you how to get a frist date. They're awful if you want anything more than a first date. Sure, getting the first date is the first step, and the one that a lot of people have trouble with, but a lot of the methods those books teach set you up for complete failure long term.
The only really true fundamental they'll teach you is to be confident in who you are. People say 'be yourself' a lot, which is only part of the equation. You have to be happy with who you are, and expect other people to like who you are. Then you'll be yourself without even thinking about it, and people will be drawn to that.
It's okay to be excited about talking to a girl, as long as the vibe is very clearly put off that she's also lucky to be talking to you as well, because you're awesome.
If you forget about girls first, and work on being awesome and thinking you're awesome, the girls will take care of itself.