Other side wants to know if it's logically illegal to date short people now.
Bit of a tangent, but I've noticed a bit of an over-correction with the age thing. Back in the 'good' old days, a grown ass man like 40 year old Seinfeld would date a sixteen year old, and it would be tolerated or accepted. Obviously icky in retrospect and it's good that it's now illegal. But now you'll often read people say online that a 35 year old dating or even being attracted to a 25 year old is a red flag. I mean, it may not be ideal, and age gaps can cause issues (IRC women who date older men are more likely to be abused), but adults finding adults attractive or dating isn't necessarily creepy.
I do find porn where a petite 20+ actress is clearly pretending to be younger quite problematic though. It's not so much what they look like, but how they act. Like Piper Perri, the small blonde woman from that meme with her sitting on the couch with the black guys. Looks really young even though she's 30. As you say, there's a lot of porn like that.
Obviously even having this discussion and discussing the nuances of it can make you seem really creepy, and as you say make the discussion polarising. A bit like deciding to have a discussion about how to solve Israeli-Palestinian conflict on your first day, no one sensible wants to have it whatever side of the argument they may fall, and I get why many people would not want to see anything even remotely questionable pop up in their feed even if the actors are in their 20s. If only that they don't want to have to explain why they're subscribed to that content to their significant other, family or friends.