Just compare it on "What to Mine". I am using Flypool, Nanopool and NiceHash and I am getting best gains on NiceHash. I am not keeping any small coins (Only ETH, BTC and ZEC). Ideology has no place when earning money, in my mind.
Youre completely right, the only reason for mining a shitcoin is if its more profitable, and you even with exchange fee can dump it for more good coin.
With 100 rx570's youre looking at arround avg 80 usd/day solo mining, 1% less on a good pool, and 81 usd/day on nicehash, so for arround 1% more profit you take the change to loose a few days to a weeks profit if they get hacked again
And if you dont wana hold the BTC they give you but want ETH or ZEC you will loose that little gain in fee's compared to mining the coin directly you wana store.