I use simple loop constructs like the above all the time; it's especially useful for collecting. But elaborate loop constructs in their full glory are impossible to understand and IMHO should be banned from use on any software engineering team.
Seen pretty elaborate loop constructs in large Common Lisp code bases I was working on, and my conclusion is that the only thing that should be banned is lack of willingness to spend 30 minutes at some point learning the loop syntax. Seriously, after you write few loops on your own e.g. collecting over several hash tables in parallel, you won't have much problem anymore.
I still feel current generation of programmers has a learning phobia.
