Why are Sigma users so loyal (I don't get it)

Talking about the DSLR bodies, not Sigma glass. I don't get the loyalty. All the bodies seem to be feature poor compared to competitors. The infamous sensors reportedly give lots of resolution, but only in bright light....color and noise in the shadows is...um..ahhh...not so great, poor ISO performance seems to be about 2 years behind not only Nikon and Canon, but Olympus, Sony, etc.

I originally just came by to see the train wreck, but I can't help but admire the tenacity of the Sigma fan...just don't understand it.