Nothing. We know cryptsy runs a shared wallet. Your deposit address is simply for accounting purposes. Coins you deposit to "your" deposit address are quickly moved to other address, and either used to fund withdrawals for other users or swept offline. At the point of CLAM distribution it was effectively random which users' deposit addresses were funded and which weren't. It was outside of the individual users' control.
It's hard to argue that those deposit addresses and the other addresses controlled by cryptsy don't belong to cryptsy, and that any stakes or other rewards received by those addresses don't belong to cryptsy. Whether they explicitly state that or not doesn't seem to make a difference.
I'm not saying that cryptsy shouldn't give out the CLAMs they received. The way I see it, it's their decision. It would look good if they did. It might attract business if people saw that they give out freebies like that. But if they think it's better for their bottom line to keep the CLAMs for themselves, or that it's just not even worth the effort to dig them up, then I think that's fine too.