The NY Times did a horse meat article recently. The article disclosed, as other posters attest, horse meat is quite common outside the US. I think it is not accepted in the US because we still hold the horse in high regard and still have a romantic attachment to horses due to the important role the animal played in our actual and imagined history.

I am among those that would not try horse meat, but I do find it strange that it is perfectly acceptable to make pet food and glue out of horses.