It is one of your options, under "settings", to receive mail from the Adminstrator. Mike's comment, " And by joining our site, you agreed to receive administrative e-mails.", may be a little misworded, therefore.
Anyone who has opted to receive such, will have the email which you have laboriously repeated here.
I may share some of your views in your first para, but perhaps it could have been worded a little more politely.
The linked site you refere to is, technically, top class. In spite of its huge following, its respons time is really fast. It has also been around, inherited from it's sister, Vista , site, for a long time and has had the opportunity to mature.At the moment, this site is going through stages of improvement, based very much on suggestions. I, myself, believe I have a reputation of being a "whiner" on site matters!
I do not see your first para as offering very much in that field. Mike efforts, whatever the personal opinions may be, are the result of hard work and dedication. Helpful suggestion would always win the day, rather than outspoken rude comment.