Totally agree with the points in this video.
In my opinion it is particularly suspicious that all attempts to prove that Tether is backed by anything till today failed or are completely useless. A coin (which only USP is the stability!) not being able or willed to fully prove its stability seems highly suspicious to me.
Anyway, I don't think stable coins cannot make it in the future. I just believe that there has to be a transparent solution for proving that there are securities backing the coin. I also think that the concept of multi-collateralized coins seems really interesting.