What happened in May 2007?
Fragment of a discussion from Talk:March 2011 Update
Have a look at the WikiEN-l archives in January 2006 for the thread "The userbox fad". That won't tell the whole story, but it will illustrate how established editors viewed an otherwise innocuous activity favored by a new generation of editors. I don't think it would be very hard to see how newcomers reacted to this response.