I am not the smartest, but....
I think
anonymous coins are a fad
fads only last a while, and then they go away
A reason why this fad may fade, is because the real world financial sector
may begin to embrace non-anonymous coins, while rejecting anonymous coins,
and comes along with large amounts of investment dollars,
that anonymous coins miss out on,
and investors in anonymous coins then sell, and go looking to invest into coins that
are being invested into by the real world financial persons.
Anonymous coins would then be a smaller niche, than the larger categories that
the real world financial sector might invest into.
( they won't likely want to be associated in any way at all with criminal or black market )
If you're right BTCD is the anon winner. Any coin can be dark when needed, and visible too. Best of both worlds