Agreed with the echo-chamber and word-of-mouth treatment that Vista is getting. I build custom desktops for myself, friends, and family, and have installed Vista without a hitch on all of them.
You can partly blame Vista for being a pig, but you must also hold some nonfavor to the fact that people attempt to install it on aged or totally underpowered systems, laptops especially. When someone's laptop comes out of the factory with an Intel graphics chip, 1.5gb of memory, and a 1.9ghz dual core, of course they're going to have a horrible time running Vista. Moreso when people are 'upgrading' from XP to Vista on an older machine, thinking themselves tech-savvy, and come to find it doesn't like their Ti-4200 AGP graphics and P4 2.9ghz; as I mentioned they believe themselves to be technically capable and henceforth bedrudge Vista when in fact they've installed a very large, capable OS on a very old, limited system.
I find the majority of problems associated with Vista and its performance and compatibility actually stem from the hardware it is installed on. Microsoft made the mistake of putting it out with minimum specs far below what it could operate decently on, or worse the minimum spec just gets ignored entirely. If the minimum spec was more inline with the recommended specification or perhaps higher, whereas the performance of the OS can be appreciated (Runs in RAM instead of dumping to pagefile ASAP like XP, hence the gripes of 'memory usage', for example), and again presuming people don't ignore the spec, Vista wouldn't be hurting so much in the eyes of the 'midline tech-savvy' crowd.
In short: Vista suffers from being installed on aged and underpowered hardware by people more than ready to misassign blame to it and gleefully tell all their friends about it.