There are many reasons to bitch about M$ in general and Vista in specific. Bitching because it doesn't do something like you may be used to, makes the person squawking seem like a bit of a twit.
Changing the appearance of screens is acceptable. If one can't take a few minutes to figure out a new system, maybe they should go back to their etch-a-sketch. Changing interfaces and such is somewhat nastier.
Changing the security system is acceptable if it does some good. Releasing a security system that degrades user experience and provides less security is open to criticism. Take all those stupid pop ups that require the user to go back and re-run as administrator and then still ask for a note from the users mother and a chit from the chaplain. If a malware distributer can get the user to run an installer, it can launch a service which can change all those permissions and bypass the pop ups while looting your system.
They did change the control panel applets. Now they can be written as a .exe and registered as a control panel applet. There is a mechanism that lets the author make it accessible from multiple panels. That's kind of cool IMO.
Some things are strictly personal preference. In older versions you can hit control-tab and tab through all open programs. In Vista, if you hit <window button>-tab you get all the open programs in live windows that you can tab through. Personally, I think it is a waste of processor power, but I know others that like it.
In general, saying something positive about a M$ product is not being a shill or fanboi. It may be a little more fair to skip personal accusations until something REALLY warrants it.
Just my $0.02