I agree you can learn many lessons about what not to do. The broader point I'm making here is that there's a billion things not to do and a few things you should do. The successful startups will also make mistakes, iterate, and teach you the things not to do but teach you how to figure out what you should be doing. The unsuccessful ones just stubbornly plod forward and you, the employee, just know you guys screwed it up, but have no idea how to find success.

TL;DR YMMV, but it's much more valuable to learn a selection of "winning moves" you can apply than it is to learn a bunch of "losing moves" not to apply.