The arguments in favor of the ban boil down to the fact that horses are pretty and nice, and we like them. The arguments against boil down to the fact that warm, soft horseflesh equals cold, hard cash.
Somewhat shamefully, the question of deliciousness never enters the debate. I vividly remember my Italian TA in college, the bellissima Signorina Mangiameli, talking about the horsemeat entree she ate in Italy and how incredibly tasty it was. And hey, if the USDA endorsed it, how bad can it be?