I think this argument is flawed. Analogy: there will always be people who steal stuff; this doesn't mean we should accept the practice, and discard any preventive measures.
I believe your analogy might be flawed. When theft is prevented, the downside is that "thieves" don't end up with more things. But when you have the right to be forgotten, you may also remove other things. For example, in an election, a candidate's running mate could easily decide "I hate this person, I want all of my work with them to be forgotten", which would severly hurt that candidate's media coverage (sure, you can still find articles about that candidate on some archives, but many voters do not work that hard to educate themselves)
But that isn't even what your parent comment was talking about. They were talking about how the whackamole game of censorship. If you put a law in place to prevent theft, it's not like thieves start coming up with places for all other thieves to come steal. On the other hand, if you censor Google Search results, there's a good chance you'll see, e.g. employers, moving to another search engine specifically for finding results people have requested to be forgotten
