Dan left because of the license limitation.
Dan said why he left in his resignation post thread, and it wasn't that. Dan was the one who chose that specific license for steemd.
PS: The NAP doesn't apply to property, otherwise contracts would be meaningless. :)
I would love to have a friendly debate the nuance of contract law. Since we have 255 depth, I'm game. I would use the @marcstevens criteria for discovering if there's a violation of individual rights. It starts with finding a forum with jurisdiction to enforce its ruling.
Sadly, I cannot discuss the details of this particular matter, though I look forward to discussing such things with you in other contexts here on steemit one day. :)