That's true. Jack and Martha clicked because they could empathise with each other about the Doctor, though personally I hate when people say the Doctor is Jack's one true love, I tend to see Jack as hero-worshipping the Doctor. Yes, he probably is attracted to him, but he knows nothing will ever happen. He's hurt though by the way the Doctor dismisses him. Sorry,. I seem to have wandered off topic! I'm not sure the Doctor even believes that Jack is capable of having a relationship with anyone. The Doctor does get territorial over his companions, as you mentioned earlier. He doesn't want anyone hitting on them.

There ARE people out there who like Gwen, but there are more people that don't like her. Most of the pro-Gwen communities shut down long ago.