The Jedi Order has a strict policy regarding its members and love, that being that platonic love is acceptable but not romantic love, because attachments like that can lead a person away from the light side of the Force, or some other stupid reason to ensure that Anakin’s and Padmé’s love is forbidden. Because every story ever needs forbidden love, as opposed to a developed and believable relationship. But I digress.
Looking up the whole Jedi-celibacy issue, it seems to be a rather new thing that didn’t get mentioned until the prequels, and that before the movies Jedi were allowed to marry and love as they pleased. I don’t know much about that, since I’m going solely by the movies and animated series, but if this is true, it does strike me as something added just for the sake of having a forbidden romance.