Jobs didn't run Apple into the ground.
Yeah, he did. After initial great success, the MacIntosh and the Apple II that Apple developed later were not selling well.That's why Jobs hired Sculley in the first place, to boost sales. Jobs headed the MacIntosh division, but it was the Apple II that accounted for most of Apple's sales. Apple had a major cash flow problem. Many employees left. And even Woz later said that he thought Apple was going in the wrong direction, prompting Woz to sell most of his Apple stock.
https://books.google.ca/books?id=zC...n1Np8&pg=PA35&redir_esc=y#v=onepage&q&f=false
He was fired for being tempestuous and impossible to work with by Sculley and the board of directors.
Jobs actually wasn't even fired, he was simply asked to step down from the MacIntosh division:
Instead of doing that, he resigned from the company completely.
The company was driven into the ground in the late 80s and 90s by poor management, terrible products and bad decisions like licensing the Macintosh OS to clone makers.
Sculley kept Apple afloat for a while but after he left, Apple took another tumble.
NeXT ended up successful insofar as it was bought out by Apple and a lot of NeXT's software became core Apple products like OS X and Web Objects. Let's not also forget Jobs also funded Pixar with his own money and look where he took that company.
If NeXt was really successful, it wouldn't have been bought out by Apple, it would have flourished on its own. NeXt was somewhat profitable (after it turned into a software company), but never truly "successful". Jobs did some good innovative things with NeXt, which is why Apple eventually bought it. Jobs also learned a lot more about managing a company at NeXt, just as he did at Pixar.
By the time Jobs came back to Apple after 12 years, he was a lot more experienced and seasoned as a CEO.