3. Ignoring That The Doctor Is A Bloke Would Seem Dumb
Take away the context of the show's history for just a moment. Humor me. What you've got is a man who likes to have adventures in space and time with pretty young women. He plucks these women from their homes. Sometimes, like with Amy, they don't even pack a change of underwear. He and this young women live together, alone, in a small portion of the Tardis. They travel together alone for months or years at a time. They investigate crimes, see wonders of the universe, and face death and danger side by side. You have to address the possibility of romance in there. If it weren't the Doctor, if he weren't as much of an oddball sexually as he is, they'd all be falling in love with him. It's a situation that begs romance: what's strange isn't that the new show is finally addressing this screamingly obvious fact, it's that the show has managed to arrange it so that most companion-Doctor relationships aren't romantic now that we're not all pretending they can't be.