As IEven for people who disagree with PETA on the issue of euthanasia , I would ask this: Do you hate every animal shelter that euthanizes surplus and unwanted companion animals too?. There are young, healthy and unwanted companion animals among them.
People getting upset over this situation need to realize that in these cases, PETA and animal shelters are often doing society's "dirty work". The real blame tends to lie in the hands of those who supply the unwanted animals in the first place, such as puppy mills.
You are rationalizing their position incorrectly. PETA is not a shelter who tries to place the animals first and when that fails they put the animal down due to over population in the shelter. I have no problem with that. What I do have a problem is with PETA coming in and killing the animals since they do not feel as though the animals should be a pet or that live in containment is worse the death and thus put them down or release them into the wild where they will die anyway.
Two totally different dynamics at play here so you can not lump them together. While the end result might be the same in the animal being killed the path to that point is very different when a shelter and PETA are involved...