No I don't accept that answer.  I play the "traditional" way too for a
long time now.  It is very clear that being able to jump until your
head just about hits the ceiling is some kind of exploitation.  When I
press the 'jump' button, I'm jumping up a few inches only.

I've seen fast running players but every once in a while, you see
someone running really fast!  The fact that I only see this happening
every once in a while instead of all the time tells me that they know
an exploitation or are using some kind of speed hack.  Most likely the
latter.