Classic example of a small very motivated team with free reigns vs committee development at IBM. The irony is that less than 20 years later IBM would do the same thing and it lead to the IBM PC.
Did IBM consider the PC a successful product? Especially over time it's eaten their bread and butter mainframe market and they pulled out of the end user computing to Lenovo. On the flip side if they didn't do it, others were already trying.
At least for a couple of years it was a massive success. If they had not done the PC somebody else would have become the PC I think so they were damned if they did and damned if they did not.