A large % of the unconfirmed transactions are micro transactions, like 1 satoshi. Its a coordinated attack my those running BCH.
Yup, it's precisely that.
There are an alarming number of transactions like these -
https://blockchain.info/tx/50af90e80e3acfb78bc62f6837d22bec7f0024b5d1d2263f08af6d473a1999f5 clogging the pipe.
Of course some miners are in bed with the people behind BCH to let this happen.
I wish there was a way to drop all these micro transactions (below $5) from the mempool altogether. I suppose it would clear the queue by about 70% if not more.