The history of large exotic reactor designs is poor. Sodium-cooled reactors have sodium fires. Helium-cooled reactors have helium leaks (The Ft. St. Vrain story is sad; good idea, but some badly designed components in the radioactive section.) Pebble bed reactors jam. (A small one in Germany is jammed, shut down, and can't be decommissioned.) Molten salt reactors require an on-site chemical plant which processes the radioactive molten salt. Chemical plants for radioactive materials are a huge headache and have the potential to leak. With pressurized water reactors, you only have to handle water, not radioactive fluorine salts.
All designs where the radioactive portion of the system has much complexity have had major problems. Fixing anything in the radioactive part is extremely difficult. But the reactor has to run for decades to be profitable.