500 hours on type is absolutely normal for most CAAs in most countries; you can view it as a safety factor or protectionism, take your pick. I'm not talking about Cessnas, I mean on heavier commercial metal. It's no different in European countries, most CAAs won't do validations for non-JAA licences for F/Os, and for Captains only if the airline can show on paper that they have tried and failed looking locally.
I knew some experienced expats who flew MD for a few years in another African country, the airline took A320s and tried to swop them onto the type, the local CAA said no as they should have 500 hours on type, end of story and the expats had to go.