You also conveniently forgot blockchain notary, which is actually pretty big.

600 BTC is worth around $225,000 at the moment and could go lower.  I've worked closely with a number of start ups and the cost of having a team of 1 full time developer, one part time dev, and one part time chief scientist would typically be around $15k per month on the low end.  So basically 600 BTC gets them around 15 months of runway under normal start up circumstances.  However unlike normal startups, altcoins can't expect to have the opportunity to raise more capital through later rounds of funding, so the right approach is to be insanely frugile if you want to keep things going for 3 to 4 years.  Expecting him to be spending on much more than the team he currently has would ensure the project doesn't have the runway it needs.    

There's likely a lot more going on behind the scenes than you realize.  For instance, I also work closely with Darkcoin, and helped put together the Darkcoin foundation.  While it might seem like a trivial project, it took us just under 6 months to get it up and running.  Also, we were hesitant to announce anything about it until we knew for certain it would go live.  

Just because we don't hear anything doesn't mean things aren't happening.