But then people use excuses like "I have thick skin, I wouldn't be offended if someone else said the same thing to me, I prefer honesty over decorum", etc. Most often these people come from a privileged background where negative feedback rolls off more easily because they know that, at the end of the day, they'll always have a comfortable life without any serious hardship.

One thing that I learned in a training at work is the platinum rule: Treat others the way _they_ want to be treated.