Exactly. This is a "thin end of the wedge" argument.
If you agree that certain actions can be moral in limited circumstances, you also agree to support the moral logic they're based on, on principle - even if that moral logic does huge harm elsewhere.
It's a superficially clever rhetorical argument, but it's not a very moral one.
If you're a poor person, you don't want to be in situation where PETA are offering to interfere in your life to make a political point - you want to be in a situation where you're not poor in the first place.
There's no point saying that bandaids can stop people bleeding and people who don't want to use them are bad, if you don't address why there are flesh wounds everywhere you look.
Are bandaids better than nothing? They are. But there are still people trying to fix the flesh wounds. Does the author support them, or not?