I can understand your love for horses but I see it this way: Pigs are also lovely intelligent animals, so are cows and sheeps and still we slaughter them in their millions and eat them with no regret. To eat a horse is not a sign of a uncivilized culture, but rather that the food tabu is different. In Iceland it was actually forbidden to eat horse meat before the 20th century because it was seen as a heathen custom, since eating horse meat had been a part of pagan rituals. But when it was again allowed to eat horse people started eating them again.
The horse culture is also so much different here in Iceland. We only have one type of horse in this country, the Icelandic one that is a horse that was brought to the country by vikings and made stronger and sturdier by the environment, and is very similar to the original european horse. Even though there is a great deal of horses trained to ride, there are great big herds of horses that are basically wild and are kept in mountains and heaths, and those are the horses that we mostly eat. Of course there is the occasional riding horse that is slaughtered because of injury or other things, and instead of letting his meat go to waste he is eaten, simple as that. There is of course people in Iceland that are against eaten horses, but in my experience those are all people that have grown up in big towns with little experience of animals. The horse breeders that are more rural in mentality have no problem eating horse, and see it as a normal thing, kind of: why let it go to waste?
I hope this clears out why we eat horse meat in Iceland. They are considered pets in Usa and many european countries, but in many countries its considered barn animal as the pig and cow, and since its a herbivore I really cant see the link between eating a cat (carnivore) and a horse, but I understand why you would see it that way.