
Because of the lack of Christian iconography we see in both films and the book it is safe to assume that this specific who society doesn’t believe in the existence of a higher being other than Santa especially since the adults believe but the belief in Santa implies some knowledge of St. Nick BUT the society that exists on the speck of dust in Horton here’s a who do not celebrate nor acknowledge a higher power other than Horton only after irrefutable proof so my hypothesis is that
the whos ancestors on the snowflake once engaged in trade with other molecular level whos or maybe even whatever species that the grinch is from and the other whos had a who Jesus and a who Bethlehem and a whosifiction where they were a fully Christian society but the who’s on the snowflake conquered/colonized them thus adopting their practices without any religious understanding and that is why the grinch is the last of his kind