Were monitors poorly designed for the battle they faced?

Were monitors poorly designed because they were so vulnerable to mines?

They were effective against artillery, the threat their design emphasized. Greater resistance to mines would have required more subdivision and further design work.

Monitors were wartime designs built around a small exposed target and armor that resisted artillery. Those features suited an important part of the fighting at Mobile Bay. Better mine protection would have required more design work and internal subdivision. Losing a ship during a dangerous attack therefore does not by itself establish that the type was unsuitable for its intended task. The discussion also connects the monitors' gun turrets with later developments leading toward the dreadnought battleship.