I think it's just the sheer amount and content that's the problem. Think back to like the 80's and 90's when your porn viewing habits were dictated entirely by whatever magazines or tapes you could get your hands on, so there were fewer troons because most guys who believed they were straight wouldn't even consider buying gay/tranny stuff. Kids who grew up with PornHub would be much more inclined to at least take a look at stuff that their parents wouldn't have even had access to when they were the same age, because they could find thousands of videos of shot they wouldn't have even thought about if the website hadn't suggested it to them.