Very few restaurants have them (especially those without bars), and the ones that do never clean the pump head so it's always covered in dirt and bacteria. At least I know that the soda fountain nozzle(s) gets cleaned nightly at most restaurants. But nobody ever seems to sanitize the flavor pumps.

Plastic pumps separate from the fountain? I’ve seen them once or twice but I couldn’t name a chain that I’ve been to which has those. But also you’d have to know the ideal ratio of syrup to base soda rather than have it pre-mixed.