While watching the rather amateurish "music of Star Wars" DVD that comes (for free, thankfully) with the Revenge of the Sith soundtrack, I pondered one basic problem of the Jedi order:
Being strong in the Force is at least somewhat biological, depending as it does on magical mitochondria. We know strength in the Force can be passed to children (e.g. Anakin to Luke). So if the Jedi recruit those who are strong in the Force and then prohibit their having children, doesn't that mean they're in danger of breeding out Force aptitude?
m suggests that this is intentional.
The Republic wants to keep the Jedi down. After all, if Jedi just started hooking up left and right, they'd have super-kids in no time and it would be all over for the normal folks. The "no love" provision means that they're forever stuck with the baseline incidence of Force sensitivity as found in the general populace. It's a sort of preventative eugenics program.