While NeXT might have been a commercial failure, the vast majority of entrepreneurs can only dream of having such a business once in their lifetime. In the end, NeXT was acquired by Apple and the foundation of their operating system became what is now OS X. NeXT would not be called a failure if any other person had founded it - it just seems less successful by comparison in the light of Jobs' other endeavors.
If NeXT hadn't produced a pre-emptively multitasking, memory protected, highly object oriented operating system and software development ecosystem, NeXT wouldn't have been acquired by Apple, and Apple wouldn't have had the key technology that has powered every major success they've had outside of the iPod in the last 10 years.
Remember that Apple wasn't shopping for Jobs, they were shopping for a modern OS; they only turned to NeXT after Gassée fucked-up their deal to buy Be.
Financially NeXT was a wash, the $400 million paid for it was enough to pay back most of the investors, so they got their money back but no profit.
For Apple, having the NeXT talent and what became OSX, it was a success for them. So NeXT had value - it was not a "-1" as a company going bankrupt would be.
Yeah; if a web startup sold to Google at essentially no profit when you paid out the investors, I don't think it would be considered a failure. Maybe not a great success, but certainly no one would consider it a bad thing.
And if a web startup sold to Google at essentially no profit when you paid out the investors, and the technologies pioneered at it went on to power almost every major product Google released for the following 15 years, people would consider it a deeply influential and successful company.
People seem to grade NeXT on a very, very steep curve.
NeXT is a confusing company to judge. They were slowly dying for years, then suddenly Apple came along and rescued them. Except it turned out that it was NeXT who rescued Apple. But all the subsequent stuff was done under the Apple name, so people just remember the NeXT that built extremely expensive computers, didn't sell very many of them, and nearly went bust before being bought out.