Safety system don’t just need to handle normal operations. The energy in a fusion reactors magnetic fields is very well known, a fission reactor steam explosion or potentially hydrogen explosions can bet vastly more violent.

Using Fukushima as a baseline. ~1,000 kg of hydrogen * 142 MJ/kg is a lot of energy and that was vented outside the primary containment vessel before detonating.

Granted this is not an inherent requirement for fission, but good luck convincing regulators it’s unnecessary.