I build WordPress sites for clients. Some clients have very specific needs with regards to plugins for their site.
Sometimes these plugins are no longer supported by their original authors, so I have to do what I can in order to force the plugin to work with whatever version of WordPress I'm using at the time.
Then, later down the road, when my client is in the admin panel and see's the "Upgrade to WordPress 3.1!" message, he clicks it and goes through the upgrade process, not knowing that the new WordPress version completely breaks the functionality of the very plugin they have to use. Then they call and complain to me and I have to go through another nightmare of trying to make it work.
It's really really really ANNOYING. The automatic upgrade message is probably the absolute worst feature of WordPress in my opinion. If you guys simply added in an option somewhere in the admin panel to turn off the message that would help tremendously.
I know there is a plugin out there that does it. Too bad I have to rely on a plugin for a feature that should absolutely be apart of WordPress to begin with.
I know that you WordPress guys are trying to make people's life easier and more convenient by offering the upgrade message. But in reality, in most situations you are probably causing more harm than good. It's like all the crap Microsoft does. Like how many times have you heard about people complaining about the auto-formatting feature in Microsoft Word? It's there to try to make your life easier and more convenient. But in the end, most users just want to turn it off so they aren't fighting to make their document look how they want it. You are doing the same thing with your upgrade message.