On reddit, Machiavelli when or drawn upon, it is often mentioned with it that The Prince was actually satire.
This doesn't cover everything you asked, but a recent take on this question might be revealing until someone comes along with a full answer: https://www.reddit.com/r/AskHistorians/comments/4530h0/why_did_enlightenment_philosophers_try_so_hard_to/
Hi, the floor is always open for more discussion, but meanwhile you may be interested in this most recent post on the subject