Agreed. The Doctor's ingenuity and personality is what is integral to the character, not necessarily the gender. It would seem pretty obvious to me that, as fair as the series has generally been (compared to many, many others), it has still maintained a purely male lead for specific, gendered reasons.
At the same time, I don't want a female doctor just because it's an antithesis to the mold, and I feel like it would be interpreted that way due to the subtle (and not so subtle) ways in which Doctor Who/Torchwood has pushed a variety of gender/sexual relationships to the forefront in recent years.
I want to see it happen because I honestly think it would be an interesting twist on the story of the Doctor that hasn't really been tackled yet. But once again, it is the Doctor's "nature" that makes the character so easy to idolize. I hate this argument because I feel that it, oddly enough, only really matters to the adult male fans of the show. Kids who love Doctor Who, and (I realize I'm making a bit of an unfounded leap here) a large portion of the female audience would undoubtedly still watch and enjoy it if the Doctor was a she.
