Here are some bitcoiners and bitcoin developers talking about why privacy and fungibility is important. This might help to explain why so many of the bitcoin developers have been interested in coinjoin and confidential transactions:

http://diyhpl.us/wiki/transcripts/gmaxwell-confidential-tran...

http://diyhpl.us/wiki/transcripts/bitcoin-adam3us-fungibilit...

http://diyhpl.us/wiki/transcripts/sf-bitcoin-meetup/2016-11-...

http://diyhpl.us/wiki/transcripts/scalingbitcoin/milan/fungi...

http://diyhpl.us/wiki/transcripts/scalingbitcoin/privacy-and...

Long-term, I expect mixers, coinjoin, confidential transactions or other technology to get implemented into the bitcoin protocol. Short-term I think that they are most likely to show up in sidechains or we'll just stick with the services already deployed (joinmarket, maybe tumblebit, etc.).

And ultimately the whole blockchain data stuff could poof out of existence thanks to the near magic of recursive SNARKs.... which isn't going to get deployed any time soon; uh, maybe on a sidechain.

That said, I recognize we're in a thread about some sort of SEC enforcement action. Stay legal, folks. Fungibility is a property of money, and if fungibility is deemed illegal then that's certainly interesting and something to consider. As a faithful internet comment author, I have not read the article at all, so I am absolutely certain that the accusation is not merely "omg fungible money" it's probably an accusation regarding a crime/scam or whatever. (Oh I guess I get a free pass-- Silly3rd's post says the mixer comment is unrelated to the article.)