I...guess...so. I don't know. I'm admitting right now that I have a very, VERY bad view of John Winchester and little to no like or sympathy for him as a character because of personal issues, and that's not likely to change any time soon. But there is something about the pairing of John/Dean that would strike me as 'John is trying to turn Dean into Mary'. I think it's just something that would always be in the back of my mind if I were to become an avid reader of John/Dean. And to be brutally honest (and I'm preparing myself for a dogpile here) I don't think a John/Dean relationship would have anything to do with love. They love each other, of course they love each other. But...

I'm not a Dean/Sam shipper either (my two OTP couples are Dean/Cas and Dean/Ruby) but if I had to choose between John/Dean and Dean/Sam, I'd pick the latter.

This is just my opinion. I'm not looking for a fight or anything, but neither of the relationships in question would be healthy in any way.

Now, as for the Dean being more like Mary issue? I've just always seen Dean as a lot like Mary. He's the son that resembles her physically and I think he has a lot of her personality in him. That's not to say he doesn't have his father in him because Lord knows he does, but I've always thought he's a lot like Mary and Sam's a lot like John. *shrug* Just my view on the character, I guess.