Here's what I know:
We don't add features to bug-fix releases.
u'' is considered a feature.
By not backporting to 3.1 and 3.2 we are not easing the migration pains
Here's what I don't know:
Why is readding u'' a feature and not a bug? (Just had a thought about
this -- because the removal of u'' is documented.)
To take a different example: callable() had been removed from 3.0, and
was added back in 3.2. callable() is not a big deal as you can roll
your own quite easily -- and that is the huge difference: a user
*cannot* add u'' back to 3.0/3.1 (at least, not without modifying and
rebuilding the Python interpreter source).
If there is already a FAQ entry feel free to point me to it, but I would
still be curious why, in this instance, practicality does not beat purity?
My apologies if this type of question has been rehashed before.