[Tagging] Why is this user editing in this manner?

[Dave F.]

Hi

http://www.openstreetmap.org/browse/changeset/12742505

I created a multi-polygon (1754193) with an outer, & a couple of inners 
to represent a riverbank with an island (there are other members, but 
not relevant to this enquiry).

To the West of this is a closed way to represent the continuation of the 
riverbank. This is contiguous with the multi-polygon where they shared a 
couple of nodes so there were two way segments on top of each other.

The latest editor has split both the closed way & outer polygon, deleted 
one of the overlapping ways & added the remaining way to both the outer 
way & a newly created multi-polygon (2338583) as a substitute for the 
closed way.

Why has the editor done this? Is there a new preferred reason for doing 
this? To me it seems a pointless exercise that adds nothing but makes it 
more confusing for any future editor, especially putting a previously 
closed way into a multi-polygon.

He's done this on numerous occasions around the South of the UK. He 
seems to think that overlapping ways is bad but his edits appear a bit 
random - notice he doesn't do a similar edit to the East of the 
multi-polygon.

Cheers
Dave F,