As a professional software engineer working in industry, I definately agree with that point of view. Profesionally developed software that costs money is more often than not of better quality. The problem is that alot of the time it costs too much for any one outside of an office/work environment. For people who want to learn a new technology, or pick up a hobby, open source software is good to have.
Most of the really good open source software out there is backed by a larger company with money and pro developers, Apache/Eclipse/Novell/RedHat/OpenOffice.org/etc...
As for a new XP/OSX replacement, I think Symphony OS (
http://www.symphonyos.com/ )shows quite a bit of promise, especially from a usability / productivity / user friendly front!