Sigh. This seems like a case of people who grew up with Web 2.0 expecting every site to be malleable to their touch. Sorry, kids, once upon a time you couldn't comment on or edit *any* web sites! People used web sites to broadcast information, not to hold conversations and network. Believe it or not, this is still how some sites work, even ones that have nothing to do with religion. I know everything the Society does is fodder for criticism, but expecting them to allow comments is ridiculous from any perspective.
The forms Jeffro mentioned are not for commenting, they're for feedback. Of course every web site has some way to contact its owner (JW.org's is at http://www.jw.org/en/jehovahs-witnesses/contact/united-states/), but that doesn't count as commenting.