It's normal thing, all faucet owners adjust faucet rewards by usd/btc rate. Look at bitcoin price, it never was so high and faucet owners had to reduce their rewards. Another reason why thy may decrease rewards is income from advertisements. Maybe they earned not enough income from ads to keep site profitable with current reward rates.
This is the most possible reason why faucet rewards decreased. Since it's a so called business of faucet owners, they have to that so they will not loss their so called business which is they just get profit from faucet as mentioned above.