Are you trying to justify arguing that they're not actually at a high stress level? That doesn't seem very nice. 3.5 and 4.5 are perfectly within 1 to 5 so I'm not sure what you're getting at here.
1-5 with half increments has 9 possible scores which is basically the same as 1-10. I think this is what is meant, not "people say 4.5/5 but nobody is really that stressed, they must be thinking 4.5/10".