Depends on what you do. If you're starting a new project picking Theano indeed isn't a very good choice due to the reasons you've mentioned. However, if you already have a stable piece of software that does what you want it to do then migration won't add much value and you could spend this time doing something more important, like improving documentation or having dinner with your family and friends.

However it's worth pointing out that theano's API is somewhat similar to tensorflow so migrating shouldn't be too hard and should be fairly easy to test