It took almost 12 months between the Gingerbread/2.3 release and my phone actually getting updated. It has a vanilla Google interface, manufactured by HTC and a small amount of crap/carrierware. They can't do the simple 2.2 to 2.3 upgrade in a reasonable amount of time where none of your reasons apply.
Put in perspective - it took about 12 minutes after finding out about a new iOS release and having it on my device, and 12 months for the Android device.
Yes, for some phones it takes a lot longer or some never get an update. But I think the discussion here was about how fast can an ICS update come? Gingerbread updates and Froyo updates started rolling out about 2 months after they were released. It took 4 months for ICS to upgrade from 2.3, but about 2 months for Honeycomb tablets. Plus there's the whole issue that manufacturers wanted to renew their skins as well.
Put in perspective - it took about 12 minutes after finding out about a new iOS release and having it on my device, and 12 months for the Android device.