I am not good with technicals, but I totally understand why darksend is closed source... I dont understand why even a bitcoin core dev participates to inane whining about it, the reasons for temporarily closed source are obvious.
After reading through that thread it is pretty clear that GMaxwell is mad that his coinjoin was used for the basis of an altcoin. Dude is clearly one of the "Bitcoin is all we need!!" types and resents having any association at all with DRK -- even if that association is just that something he worked on in the past
and made public forms just the basis for Darksend.
In short, he has a personal vendetta going against DRK and I would ignore anything he says on the subject becuase of the obvious bias.