Because this is the best pool and gives 0.0024-0.0026 for each S9
Some people just don't understand...
Look at the latest blocks. Other than the empty block (yes, AntPool is STILL mining empty blocks, even though there are nearly 200k unconfirmed transactions) each block solved by AntPool today has averaged over 4
BTC in fees. Every. Block. As of this post, that's 77.14335391
BTC AntPool has kept for themselves since the day started.
Let me put that in bold for you:
77.14335391BTCThey've solved 18 blocks so far and generated 225
BTC from those solves.
They have kept 34.29% of your earnings.