The X server architecture, designed long time ago by some happy hippies who just thought all the people are good and non-malicious Oh noes! I just found the following security vulnerability: someone could smash their way into my house, and then threaten to hit me with a large pipe unless I gave them my bank information. Damn those hippie system designers that didn't include an armored work area!!!
The bad press X gets is like banning HTTP because someone broke into your webserver once...