Considering that Sony listened to us customer making Lollipop for the middle range phones like the Xperia M2 soon a reality (and it will start straight with 5.1) I would say that Sony is moving in the right direction.
The M2 together with 11 other Xperia phones (Z series obviously included) is also part of the Android M developer preview now. Which is what I want from an electronic manufacturer: support for the less recent models.