Brainrot is a very unique kind of joke. To old people, it’s funny because “haha kids are stupid.” To middle-aged people, it’s funny because it sounds like a meme and that on its own makes it funny. To young adults, it’s funny because it’s an ironic meta joke that’s funny just because it’s supposed to be funny even though it really isn’t funny. To teenagers, it’s funny because “haha old people are stupid because “haha kids are stupid” so let’s play a prank on old people to make them think we’re stupid.” To kids, it’s funny because it’s funny to teenagers.

So I dunno take your pick. Also marketing and sales people can be notoriously up their own ass and out of touch (see the Wendy’s “memer” commercial) so who knows why they do things