Merit Holders have an incentive to use one key per Merit, despite the fact it's:
Harder to manage.
Requires a modified node/running multiple nodes.
Harms the network.
It means they can avoid Merit Removals though (via only losing a percentage of their Merit). Because of that, a counterbalance is needed. Increasing the difficulty for new miners by 10% will do this.
It also increases the barrier to entry, and further incentivizes pools, but it's only for a single block and it's not 100%. It's enough to make any miners who want to dance around the system because they can reconsider.
Merit Holders have an incentive to use one key per Merit, despite the fact it's:
It means they can avoid Merit Removals though (via only losing a percentage of their Merit). Because of that, a counterbalance is needed. Increasing the difficulty for new miners by 10% will do this.
It also increases the barrier to entry, and further incentivizes pools, but it's only for a single block and it's not 100%. It's enough to make any miners who want to dance around the system because they can reconsider.