The most likely explanation, which was suggested by someone else but unfortunately I forget who, is that the founder of TwitPic was simply tired of dealing with

The most likely explanation, which was suggested by someone else but unfortunately I forget who, is that the founder of TwitPic was simply tired of dealing with Twitter and their increasingly-hostile stance towards third-party developers (even though in this case it's a service and not a client). This trademark thing may have just been the final straw. And in light of that, being acquired makes perfect sense as it means the founder still gets to stop dealing with Twitter and let the new owners deal with them now.