SNIP

>Why do that when it is not necessary, but ignore mdot when it certainly can be necessary?

If you find yourself that it is necessary, it already is an indication there is something wrong. Column names should not conflict variable names in the first place. Granted, there are situations where this is out of your control, but in general your naming conventions should avoid this at all cost.

To answer your question directly. For me it affects readability. As like Lutz, I hate it passionately.