I have been discouraged (read: told "don't do that!") from using a "simplified versions" book of famous pieces, and I've read also here many questions (for example this one, or this one). They ask, however, in terms of right and wrong, without detailing why is it wrong, didactically.
For instance, I was learning this version of Für Elise (second part):
and for comparison, this is the full version from IMSLP of the same bars:
So my question is:
What are the didactic problems in learning a simplified version of a piece?
Apart from for instance having to learn the piece again in its full glory. I've added those sheets so that, I hope, answers can go into details with practical examples, since all the answers I get from my teacher (and other skilled musicians I know) are the same: I don't like simplified versions, just wait.
I'd like something more than the "it's wrong" I am hearing.