I use Linux on the desktop since 2001. Used many distros. Also I gave something back: I'm the author of two desktop applications packaged into Debian and many other distros. So I'm no Linux detractor.
That said, throughout the years, I witnessed a constant stream of regressions during updates. Regressions happen in every aspect the of the system, from kernel drivers, codecs, sound system and specific apps. To make it worst, most distros, including Ubuntu, deal with regressions in the usual open source way: if there is interest and time it will eventually get fixed. Months or years can pass. IMO this is unacceptable for businesses. This lack of quality may very well be the reason Linux desktop has not taken off.