Why would they add Darkcoin? Didn't Finex de-list Darkcoin because nobody used it? My theory is that the shady Russians wanted some type of mixer for their scandalous activities and aren't convinced a monero wallet will ever come out.
Exactly. Doesn't matter that monero offers total anonymity, it will never go anywhere as a currency or a store of value. They simply forked their tech and never progressed with anything except bugfixes, no marketing and also no features.
Atleast DASH can be used for fast transactions and a good enough level of privacy. I believe there are far better alternatives for this, but not with a huge enough marketcap/liquidity.