The video is indeed... not so great. I would go as far as to say that this might be the Kickstarter campaign with the crappiest video that ever succeeded.
But at some point I just had to launch instead of continuing to hope I would eventually get around to launching the perfect campaign. I did however make an effort to give non-Emacs a better glimpse into how Magit works using a few articles listed at [1]. You might also want to check out some of the screencasts that were created by users [2].
[1] https://emacsair.me/2017/09/01/campaign-articles/#start
[2] https://www.youtube.com/watch?v=rzQEIRRJ2T0 https://magit.vc/screencasts