Other folks have pointed out that NeXT had a successful exit and the software lives on, to which I'd add a nice continuing career path for many of its employees (with Apple).
Those folks are missing the point. Next was bought and brought into apples ecosystem thats were the found sucess none of that was part of any plan. Again luck and timing, ifJjobs hadnt been introduced the chances of Next being incorporated into Apple would be much less likely.
That seems like a high bar for 'success' that I'm not sure many share. Lots of startups people deem successful had exits that weren't originally part of the plan. Luck and timing are huge parts of 'success'.
We are talking about companies who are successful because of their product/services/business. Not companies who get saved from going under by some other company. Next was saved.