otto42- this comment is a bit dated, but I feel I had to respond. You said:
"If all you want is to post on a blog and you want to pay somebody else to maintain it, then do that. Why did you buy your own hosting? Why not find somebody who will manage your website for you and will leave running the blog content to you?
WordPress.com offers just that service, in fact. You can set up a site, get your own domain name, etc, etc. No technical knowledge needed."
I'm one of those people who is almost happy with that, but wordpress.com has some pretty severe limits, e.g. no plugins, no PHP or HTML templates, etc. that make wordpress.com largely worthless to anyone who wants even a tiny bit more than the stripped down functionality provided.
That means we need to run something on our own. What I'd like to see is an upgrade process that checks the modified files, makes copies of them in a separate location, and tells you that you need to reapply changes to those files. It can still be left to the user to work out whether to overlay them, edit them, etc. The wp upgrade process is never very clean, with always some hitch in a php file somewhere, or a database schema change, or a change to one of the base templates that breaks people's themes.
That's why people are complaining. Telling them that they shouldn't be using wp and should go to wp.com is either underestimating what they're doing or overestimating what you think wp.com is good for.