Oh you guys are breaking my poor Texas heart. I can totally understand how it would be perceived as an actual bock beer, but really it's just a dark American lager. For some reason the perception is that if bock is in the name then that just means dark. Not sure if anyone has heard of Zeigenbock. It's a beer made by Bud that apparently is only made at their Houston plant for Texas distribution. It's considered 'manly' for BMC drinkers to drink a bock beer because it's dark.
Now, with that said, Shiner Bock is actually the beer that got me into beer, and their family mixpack is what got me to realize their is more to beer than the adjunct style. I'll always have a special place in my heart for good ol shiner, and used to be the only decent beer I could get at a Rangers game.(Now that we have about 20+ breweries in the dfw area the selection is much improved).
Edit: I say the perception in Texas is that bock beer is just a dark lager, but maybe that's just been my experience. The first dark colored beer I brewed was a Belgian double and when I let a friend try it, who was a strictly 'Kerrs Draw' kinda guy, he said it was the best bock he had ever tried.