Whoah! Posts in a forum now have to be necessary?   What a utilitarian perspective. Let me fetch my simple peasant's garb of sack cloth and tonight I shall sup on gruel. No longer for the world of unnecessary excess and mere frivolity. Come, brothers and sisters, let us sit in silence, and type only messages of great import.

If necessary means essential to the general good, or to the success of the activity in question, then anything that tends to encourage good grammar and punctuation in a forum where the only means of communication is the written word must be necessary.

Now, whether a post from someone who professes not to be a Morris dancer or a potential Morris dancer, bemoaning a supposed problem in the ranks of people who actually are Morris dancers is "necessary"...

But surely the whole point of an internet forum or discussion group is that it is creative and enjoyable. I liked the post comparing grammar and punctuation to music. It was a good point well made.