I agree, having a high number of edit
does not signify creating high quality content - it may only
attest to the high use of semi-automated tools for minor edits.
I also don't dispute that anon's can contribute high quality
content, and they do a lot of edits. My point was:
* anon's don't contribute significantly to most content on
Wikipedia that gets peer reviewed (as Pierre noted, by that time
they've probably registered anyway);
* hence majority of Wikipedia's GA+ content is not written by
anonymous editors (but the GA+ content is only a small percentage
of Wikipedia's total content);