Some players have the ability to do both. Kazee himself was a corner who was moved to free safety. I'm not opposed to trying whatever's necessary to find the best player at each position.
Quinn moved Kazee to safety because he was too slow for CB at he NFL level, moving him to middle safety and playing in space facing
the QB seem more suited for him - and it worked as it didn't slow down his INT production.
Robinson is a much faster and a much better athlete than Kazee. i think he had 4 INTs his final year at Tulsa while he was at CB. The Cowboys immediately gave hint that he would be
converted to safety his rookie year.
i'd already thought of Kazee as a converted FS before he was drafted - ditto with Desmond King who had INT skills as a college CB.
But it's also about the team and coaching staff that know how to best place players in the best positions, not all teams and coaches know how to do that.