Debian is traditionally best suited for such an environment, as it is designed to make things transparent and easy, and does not hide and complicate things in order to make it look easier.
Such an environment has also some conflicting requirement to many efforts of the last time. Target is not some person being administrator and user of a single computer, but to help an administrator to build a usable system for its users.1
Usability for the users has many aspects: Different users (especially with experienced under them) want to configure the system each in a way they know. Most importantly they want to use their favourite window manager. On the other hand users coach each other and ask each other how to do things. (Especially with dedicated rooms full of computers.) Thus they still should be able to do the same, even in different settings. A user2 does not use the spreadshead program looking the most similar to his window manager, but the one someone other can explain or has the features he wants. And he gets confused and complains, if this one his hidden from him.