I wouldn't be writing this particular point if season one of Sherlock had only just been shown. Because back when that was first broadcast, the character of John Watson would have been considered to be the interesting one. He had the limp, the background in Afghanistan; he was basically a very well rounded character with as many quirks as Sherlock had. But somewhere down the line it was almost as if the writers stopped writing about John Watson and just made him well... dull. His character is effectively a blogger who just got married now. There doesn't seem like there is anything interesting left in his story, unless the final instalment of season three introduces something. On the other hand, Lucy Liu's Joan Watson still maintains that early interest. The character is complex, we see her dating, she has a bit of a thing with Mycroft Holmes, and she is still harrowed by what happened to her when she was a surgeon. The other key change in the Watsons is that Joan isn't ex-military. She was a civilian surgeon, and I think this simply opens more possibilities for storylines, especially in a version of the show which has to fill a great number more episodes. I think this is one of the reasons why Joan is so much more interesting than John has become there are only so many murders that can take place, even in New York City. The rest of the time needs to be filled with character development and for that, you need to have characters worth developing. Joan simply has more time to be fleshed out on screen, and the character is better for it.
