It is also browbeating - something Duxwing has been more and more inclined to do. It kills diversity of opinion and purpose. Not everyone is here to have their words nitpicked to death, or to be held accountable to the same someone pestering for clarification to the point that it kills discussion.
So, specific instances aside, the whole 'why' is a matter of the long term behaviour patterns exhibited, and the impact they are having on the forum. Dux posts so prolifically that he has a deep influence on the way the forum is. Not everyone may feel personally affected by that, but a significant proportion of posters are.
The way we've chosen to deal with it is taylored to Dux, though it wasn't our prefered method. We tried describing to him in discussion, including numerous points of fruitless clarification, what his actions were and how they were received by others. Yet endless regressions don't get the problem solved. I'd hardly find this appropriate for anyone else, but in this case, Duxwing's personality virtually necessitates it. It's an attempt to help him adapt his posting behaviour, via the clearest means possible.
Plain, black and white, unambiguous.