Another thing, since it is miners not nodes confirming withdraws or merge mining a sidechain, this is also why bip300 could be activated without user consensus.

If a majority of miners activate it, and users hardfork, they would temporarily be less secure than the miner backed chain.

This balance of power is by design.

Drivechain is just one person in a mexican standoff on hot day sipping some water and offering it to everyone else holding a gun at eachothers head.