So it would seem that many people in Europe unknowingly have been eating horse meat.
They did not know they were eating it. It was in many popular meat sauces, meatballs etc...
The key word here is POPULAR. People were eating it, and liking it. Coming back and buying more of it.
I'm sure some people evern made comments such as "dude, this meatball sandwich is awesome!".

So here's the question: If you found out the meat you have been eating (and liking) had been mixed with horse meat, would you then be open to eating horse meat or would you be disgusted and shy away from processed meats?