Have you ever been the most supportive & nice boss going to someone? Letting them have all the time off they need, praising all they do, recommending them for wage increases....
Only then have them moan a lot about stuff until they leave your organisation.
So then you make a lovely speech about how much you will miss them, but wish them well.
Then find they stab you in the back in their exit interview?!
I mean I just honestly would never behave that way. WTF is wrong with some people?
I just wouldn't ever behave like that.