Easy access to fancy formatting would make posts worse, not better. Just look at any of those forums with buttons and see what bloating forum signatures people add to their posts.
Mosts posts don't need need more formatting than paragraphs and code tags. Italics can sometimes help if used very rarely and as skillfully as Arany János did in his poems. You do sometimes need other formatting, and some ideas are even best to be shown by a table or drawing, but it would be foolish to advertise such features or they'll be abused.