The person in question cannot speak English
They had their fingers mauled by a Pitbull, and hence can't use a computer keyboard
They have an acute case of forumaphobia
On the other hand, there are only two good reasons why you might not post:

You have no time
You can't work out how it's done.
I can't solve your time issues here (though I may be able to here). What I can do here is take you by the hand and show you how forum posting is done, Indeed, here are three videos that will show you everything you need to know. They are only a couple of minutes long each.

Video One - How to Register

Video Two - How to Enhance your Profile

Video Three - How to make a Posting

If you're new to the Internet and to forums, just work your way through all three of these videos and you should have the hang of it all by the end. If you're already reasonably confident but can't work out how to upload your picture to your profile, start with video 2. However you do it, when you've finished, dont forget to start posting to the forum!