To be truthfully honest it doesn't matter either way or even if there is something "better" out there (if Theranos was...).
TensorFlow has already become the winner from my reading around it so I'm going to continue learning it rather than another framework until I've become fairly proficient. By which time why change?
TensorFlow does not make AI or DL "more accessible". It's not easier to use than Theano. Both have good documentation, and both have lots of code examples/model implementations.
If you're looking for something that would make it easier for you to learn DL, you should try Keras - it's a higher level library, which can use both Theano and TF as a backend.
TensorFlow has already become the winner from my reading around it so I'm going to continue learning it rather than another framework until I've become fairly proficient. By which time why change?