Dash isn't getting beat up by Monero as badly as poor little ShadowCash.
But give Shen a few days, I'm sure he'll have an even easier time de-anonymizing Dash's "bad crypto" than SDC's (which was at least based on ring signatures instead of Darksend's broken CoinJoin).
I don't see the "awful mess" you're talking about. All I see is huge volume and huge price increases, backed by a great dev team and community.
Is the guy also working on de-anomyzing darksent(d)s?
No, he stumbled upon it whilst working on Ring Confidential Transactions for Monero. Perhaps if a bounty was offered he would try.