PETA is a money making scheme. They don't really care about animals, they care about getting attention to make folks open their wallets and "help" poor helpless critters. Their target audience is usually people who have little to no actual experience with animals. What better way to get attention than to say you are helping poor, cute, helpless animals, adding a bit of showmanship and the donations come pouring in. HSUS has a similar tactic, though a bit less radical. Simply put, sad animals open pocketbooks.
Anybody with a lick of animal sense knows PETA is a joke. Those folks are not their target audience. They prey on folks who love animals (a significant part of the population) but who have no real experience. Many of these folks have no experience because of their urban lifestyle, which is often paired with a well earning urban job and the disposable income that often comes with it. This is their target. Sad animals=donations.
They do love their showmanship. For most of us it is a silly joke, but if it makes the headlines they probably get more donations. "No such thing as bad publicity".