not going to work with bitcoin et al
instant distrust from everyone
personally i don't want any binary only stuff on my device if i can avoid it... and actually, i think the only such things i have are games, but at the same time many game companies have found it helps their sales by enabling devs to extend the game... look at the Source engine and all the things that have come out of that
a game that is noncompetitive is fine to be closed source because it is of little consequence
really, competitive games need to be open source too or else you get the endless bleat of gamers saying that the system is cheating them
security by obscurity doesn't work, this has been proven over and over again, and almost always, bad things are hiding in closed source binary blobs, just like Luxferre says