If no one wants to close the pools and help lower the diff, perhaps the only other option is to hardfork....have to say that most coins i see hardfork, usually die quite soon afterwards thou, so thats not an option i would vote for....
The development agenda does include activating protocol which was never enabled for us during the upgrade from 0.8 to 0.16.
I've spoken briefly about it in the past.
We can simply build clients with updated chain parameters (in source) and require miners to eventually create blocks in the new format (the regular upgrade process we skipped which uses IsSuperMajority and BIP 9 deployment).
This is at a standstill right now and has been for me ever since the 0.16 code failed to run and mine for the testnet.