I am sorry, but did you ever have to watch a movie about the area you have experience in, in which every five minutes they said or did something completely stupid because they don't know any better? That's what you are doing now. Seriously, stop talking about things you don't understand. I mean it in as friendly a manner as I can. I am not talking about camel mating because I know precious little about it, could you please not talk about the code for the same reason?
Yes, the code is old. So what. Developers rework often-visited parts of the code all the time. Your "considering how aged the current system is, it's definitely more than that" is just stupid. Yes, the project started a long time ago. Yes, perhaps a couple of places haven't been touched for years (in 99% of the cases because they aren't important and there was no need to touch them). No, that doesn't mean that adding scaling to zones in the old world is "definitely" more than anything. (Not talking about the details which are perhaps somewhat different than in the post that you reply to - but that's not important, the post that you reply to conveys the idea that this is not a lot of work clearly enough, and this is pretty certainly true.)