It's a question of being able to discuss it intelligently afterwards without having to listen repeatedly to make a transcript as you go along.
Look at the discussion thread for yourself. It's basically no analysis at all, just a bunch of comments saying "that guy is right" from people who already supported Trump.
Frankly, I think it is intellectually lazy on the part of the guy who made the video not to put his analysis into writing.
I agree that all videos should have a transcript. Surely one exists. I am going on facebook and ask the author for the transcript.