he he........... I generally have no brand loyalty to anything either......
I bought my first DSLR April 09, and I went with a pentax Km, which came with 2 lenses from currys for £380 I think. At the time, I wasn't sure how much I would get into it, and couldn't justify say £600+ on equiv spec Canon / Nikon.
Of course....I got into it, and bought loads of lenses and a 2nd body, and as Darren mentions above, if I was to swap brands, the amount of stuff I would need to sell, would be too much a pain in the backside........
So though whilst people do jump ship, it's usually quite rare compared to the no of DSLR users....... There's not really a huge difference between similar specced Canon/Nikon/Pentax/Olympus in the amateur / prosumer market.
Mostly, the quality of any image is caused by the person using it.