Because some like it like that:

@namespace url(http://www.w3.org/1999/xhtml);
@-moz-document regexp("*.stackexchange.com|superuser.com|askubuntu.com|serverfault.com|mathoverflow.com|stackapps.com|stackoverflow.com")
{
  #question-header, 
 .summary h3 a,
  #hot-network-questions li 
  {text-transform: capitalize !important;}
}