We for instance also have taboos of eating dogs and cats, but the last time I checked it was not because of value their lives, but because they are cute.

More because we regularly socialize with them. People are not, generally, in favour of killing just the ugly pets.

(And, this is purely anecdotal, but viewing animals more as less-intelligent individuals with a personality and so on and less as fleshy automatons seems to correlate with pets.)