I think it's because its growth is exponential. Well based on the charts anyway. So people can't help but expect more from it I guess. And it's not exactly odd or weird that people expect more from a coin that has already performed as well as Bitcoin, I mean at most the last ATH would probably be their minimum standard at that point. Yes, it can also be impossible for Bitcoin to not reach a new ATH, but hey, it hasn't failed us at least these past few halvings though, at least for now.

Besides, it's not exactly expensive to push out random predictions. Just treat it as them having fun imo and judge the ones that actually make sense.