Well if I have to watch annoying ads and solve 10 different captcha on 10 different sites to get 1000 satoshi, it is of course a complete waste of time. But if I only have to spend less than 10 seconds to type my username to get 0.0001 btc a day, it is much better.

Another problem with faucets is that you are collecting dusts and you will need to pay a lot of tx fee in the future when trying to spend the dust outputs. But for gambling sites' giveaway, you can get it directly on your account balance and so it wouldn't bloat the blockchain nor fill your wallet with dusts.