I think the yield seen right now are reflective of the actual amount of mining going on.

I will add some math for you:

Math with your "mining" rewards:
MH price   
0,00078499 BTC
MH reward per day
0,00001344 BTC

If you would run that MH with real hardware by yourself @ LTC network:
MH reward per day with real hardware
0,0001493 BTC

So the reward for real hardware is 91% higher than with scrypt.cc's mh.
That means the ROI for the scrypt.cc admin is 5,25 days if he is running real hardware.
Well, lets say the power costs are 50% of all rewards, then the ROI is 10,51 days

Now tell me, why should the admin not buy the hashrate out of the orderbook?