I admire DFW's writing a lot but I have to say that I largely agree with this critique of that speech (from the posted article):

"To me, it’s the least interesting version of himself he ever put to the page. But an unquantifiable number of online readers, millions of YouTube viewers, and thousands of bookstore shoppers disagree. Among the more dispiriting aspects of the Wallace canonization is how much it has been built out of his suffering — the way the cult has revived, for precisely the post-therapy, post-Romantic, self-help-soaked culture Wallace described and intermittently deplored, the Romantic picture of the depressive as a kind of keen-eyed saint."