I deleted my account because I felt irritated by Mark Baker's dominance of the site.
If you run a query for the most active users in the StackExchange Data Explorer, Mark Baker appears as the most active user, with an average of 2.5 activities per day since the time he joined:
Given the comparably little activity of most other users on this site, the intense activity of a single user becomes problematic, in that most answers, comments, edits, and votes are by that person and the site in its entirety begins to reflect not the answers and opinions of a community, but turns into something like Mark Baker's personal site.
Here is the same graph for Stack Overflow, with five activities (twice as many as Mark Baker) represented by a horizontal red line):
My interpretation of this second graph in relation to the first as well as further important arguments are in the comments below.
I have recently created this new account, because I am writing my dissertation and need something to procrastinate on. I will delete this account again when I am finished with my thesis sometime around the end of September.