I see there is deleted profiles number, how you able to tell that? profile page is no longer accessable?
I think theymos addressed this, and said that they were skipped randomly before(by accident). Source:
In the forum's first couple of years, accounts would sometimes be deleted. Also, in rare cases an ID can be skipped (eg. if a database transaction gets rolled back).
Edit:
Plagiarism etc can be easily handled due to the smaller numbers compared to accounts that just joined to get rich...
Finding posts that have used text spinners are hard, and its only possible if someone reads the entire mega thread with a shitload of shitposts.
They are handled only if they are reported.