It’s easy to be brutally honest.
To be rude, to tell a person they’re stupid, to accuse someone of dishonesty.
But what does that achieve?
It makes you feel like a big person, but it makes the other person extremely defensive.
When the counter-party has her back up, you can forget about any constructive engagement.
She will defy you out of principle, and you will both lose.
Rather park your ego’s need for validation.
Avoid the temptation to be rude (and right).
Be diplomatic.
It’s the only way to keep civil discourse, and the only way to find a solution without a fight.
Fighting kills profit.
Be diplomatic.