mutely
Raspbian as an OS is simply Linux. That's as educational as Windows, OS X, BSD, Unix. The full Raspbian Distribution deploys a few tools to help people develop, but I personally don't think that makes it an educational OS. At most maybe an educational focused distribution.
I think we are going to have to define what we both mean by "educational" here.
The focus of the Pi is encouraging education in programming. As such Raspbian, Linux and all the rest of Free and Open Source software is educational. The source code is there if you want to learn from it. You can hack on it to your hearts content.
Windows on the other hand is not. It's a back box from which you can learn nothing.
I thought Risc OS was a similar closed source black box. Correct me if I am wrong.
As for "deploys a few tools" I have no idea what you mean. Pretty much any programming language known to man is available to a Raspbian user. Normally with just a simple "apt-get install...". There are tones of editors and IDEs. What is it that is missing for you?
As for stability, Debian Jessie has it's fair share of issues. Some parts of Jessie don't even work on a vanilla install, and you can't install it and leave it running 24/7/365 without making a lot of changes. It's more stable than Raspbian wheezy was though, or requires less modifications to make it stable.
Please do elaborate on the issues you have been having with Jessie. What parts do not work?
I have Jessie systems up and running continuously for months now. On my PC, on cloud services, on the Pi. I don't see any instability. Everything just works. I certainly do install it and leave it running 24/7/365 without making a lot of changes.
Mind you, "stability" is ambiguous here. We could mean stable in that the running system does not randomly crash unexpectedly. Or we could mean the software versions are stable, API's and config formats, etc are not going to be changing for a long while.
I simply don't see how you can call Raspbian an educational OS when I don't see it doing anything over any other Linux distribution or any other OS to make it "educational".
See above. Linux systems are some of the most educational software we have, in the context of education in programming. What more are you looking for?
Memory in C++ is a leaky abstraction .