Antpool mining block with low fee spam-tx’s while mempool full with high fee tx’s.

What reason is there for a miner to place low fee transactions in a block while mempool is full enough with higher fee transactions?

The indicated block is mined by Antpool and contains 1615 small transactions going all to the same address.

Initially I thought they were recovering highly splintered BTC quantities into one new wallet, but the origin wallets seem to have several BTC in them and are continuously in use for the recent spam transactions.

EDIT: print-screen taken 13:40 (GMT+2)

Submitted August 07, 2017 at 08:00PM by Eik_NL
via reddit