Ubuntu 9.10 seems to be a worst product from Canonical. 9.10 was on a high expectation. The next release after 9.10 is going to be a Long Term Support product by Canonical Ltd. The other reason is the new Windows 7 from MS received many good responses around the world.
Most of the users upgraded / freshly installed 9.10 are hit by black screen issues. Some of the devices which worked in 9.04 discontinued to work in 9.10. It is always better to wait for any new product to arrive in the market, wait until it is reviewed by its users and then decide on buying it. The same applies for software too. I was saved by this simple idea by not installing 9.10 on the day of its release :). It is always good to be not biased.
According to a survey in Ubuntu Forums, around 33% (at the time of writing this) of the Ubuntu users seem to be affected by irrecoverable problems. May be, it is the karma of Ubuntu.
Canonical should have been more responsible. They had a very good market share in distribution based on GNU/Linux. They brought down the complex usability of GNU/Linux distribution to a much easier and simpler usability for end users. That was their success.
On the other side, Windows 7 seems to be a default version for many Windows users next to Windows XP. It seems to be a stable version too. Ubuntu 9.10's failure should have been considered as a success for some Windows 7 royal fans. They think Ubuntu is Linux.