Why do we need www?

/RANT ON
I'm not talking about the world wild west, I'm talking about why the hell do we need to type www to enter a website?

Try acessing: acer.com.

It didn't work did it?

Now try www.acer.com.

So you ask yourself what's so complicated about it?

Well, I dare to say lazyness, yes when you try acessing something without www and it doesn't work, you can call the webmaster a stupid lazy bastard, because that's what he is.

So if you are a webmaster, I'll teach you how to solve it, just change your Virtual Host * section on apache.conf or httpd.conf from this:

  DocumentRoot /home/www/web
  ServerName www.example.com

to this:

  DocumentRoot /home/www/web
  ServerName www.example.com
  ServerAlias example.com

Did you notice that I just added this line: ServerAlias example.com that's everything you need to solve this stupid problem and spare your users of typing 3 useless letters to access your website.

I still don't understand why there are some many sites out there that aren't accessible without www, it's so stupid.
/RANT OFF