Excellent article, clear, easy to read.
I'll just add what I already wrote in another thread. It is the ability to safely and easily use CoinJoin on a massive scale (and I believe that thanks to the implementation in Trezor its use will not remain marginal) that should be used to clean up the history of just even "tainted bitcoins". Why?
Because:
1. no one can be sure that such bitcoins will not get to him
2. unfortunately, no one knows who will decide which bitcoins are "tainted bitcoins" in the future.
Anyway, this first step that Trezor has taken is a step in the right direction. Let's move forward together on this journey to better privacy!