Considering the intensity of the argument, I'm sure I'll get flamed for this, but here goes:
I'm sure the Doctor would love and enjoy women, except for the fact that all the Time Ladies are dead. All he has left are the females of an extremely inferior, less-evolved species (humans). For the Doctor to consort with a human female would be like a human man consorting with an orangutan or chimpanzee female. (and consider that humans and chimps are far more closely-related than humans and Time Lords---at least chimps have roughly the same reproductive organs
Now, the Doctor certainly does have other feelings towards humans: affection, pride, etc., much like a person may feel that way towards a beloved dog. But the person wouldn't dream of entering into a romantic relationship with a dog. (or at least, I hope not)
If people want to assume that the Doctor and Romana were knocking boots in the TARDIS, that would make total sense. But the Doctor and a human would seem more like bestiality to me than an actual romantic relationship.
Anyway, in conclusion, I have no problem with the Doctor being romantic. But doing so with a highly-primitive species seems weird to me.