True, but those are not the people the men’s is making fun of. It makes fun of perfectly healthy people who decide they need gluten free everything because they heard that gluten is bad and they can’t do any research on how and why. Same with vegans who are only vegan because it’s trendy (and who probably cheat every other meal because a vegan lifestyle actually requires a fair amount of effort and learning about nutrition).
Then again, those 100 MB are usually mostly assets I want to look at or listen to. Certain websites contain 100 kB of text and pictures I want to look at and load 2 MB of JavaScript frameworks that add nothing to the usability of the site. Bonus points for automatically streaming a 20 MB video I don’t want to watch while I look for one sentence’s worth of information.