The upgrade process may be simplified but who wants to spend hours trying to fix compatibility every time they discover a bug they introduced with the last patch because they've broken backwards compatibility yet again.
What they should be doing is a general upgrade release for non-technical users and a technical bulletin about what exactly was wrong so technical users can manage older versions as desired. Instead you have to dig for an hour in trac notes to find what the heck they changed and why.
I have version 2.3 & 2.5 installs running safe because I've manually patched them and locked down the server. Delete any XMLRPC interface which is where half the bugs are introduced. The other half is the open ended admin interface which even regular users are allowed into to escalate privileges, which is asinine - you can even run PHPINFO through the admin panel as a regular member on many WP installs.