Its pretty obvious why, and thats because darksend has not delivered, and there are two other coins that do a better job that have demonstrated they work, ad then people from the DRK community trolled the XC thread and spread FUD about it.

Besides plenty of other coins are introducing anon features VERY soon, most will be implementing zerocoin but there are several different approaches.
Im glad i dumped all my DRK while the going was good, feel sorry for those who paid $16 for them.
DRK will be down to $5 next week im guessing.