Yeah from a protein prduction efficiency point of view, Pork, sheep and goats are way better than Cows. Chicken and fish are even more efficient. And plants win, hands down. We can all make choices that improve our impact on the planet.

Pigs sentience is considered very close to dogs and as dogs have a very intimate place in some culture some people make a connection and don't feel eating them.

Legacy reasons (i.e. religion), health reasons (beef is supposed to be quite healthier), maybe personal preference as well ?

Agreed. As a Spaniard, I'm surely biased, but I prefer pork to beef any day of the week.