Note that although it appears significant, that 500k CLAMs represents only around 3% of the initial distribution. There is another 12 million CLAMs out there still waiting to be dug up. There is no guarantee that the current 500k CLAM dig is the last big dig, or even the biggest one.
If CLAM aspires to be a major coin (say top 10-20) then 12 million unclaimed CLAMs is not an obstacle to doing so. At the current price that puts the fully-claimed market cap at a relatively modest $6 million.
If CLAM is just going to be a house coin on one altcoin gambling site, then it probably can't get to $6 million market cap and you should probably just do whatever you want with it, since you run the only major economic actor that matters to the coin anyway.
So while it's possible that we get through this current dig and still have some investors brave enough to hold CLAM throughout, will they stick around the next time it happens, or the time after that?
There will always be investors at some price, just as there are now.
Maybe what happened here is that the market was irrationally exuberant and got ahead of itself. Surely everyone knew that there were 12 million more coins out there. People either believed (without a strong basis for believing) that those coins would nearly all stay buried for a good long time, or that sufficient market demand existed to absorb coins that were going to be dug up. That turned out to be wrong. Investors adjusted to more realistic expectations (and perhaps continue to adjust).
There is no rational basis to say that the current price with a $6 million fully-claimed market cap is too low, at the current stage of development of this coin and community. It may even still be too high, and people investing need to really think this through for themselves, but at some price there will be investors, as long as anyone is still using the coin.
While I'm intrigued by the idea of staking to claim and perhaps slowing down the rate somewhat (and also somewhat with storage fees), I largely agree with chilly2k that trying to dictate a market price or market behavior is foolish.