This is something people say a lot on here.
I don't understand it. Genuinely.
What is wrong with disagreeing with someone and saying so and giving reasons?
If you are secure in your choices/beliefs, what do you care what other people say?
If you have some doubts, why not hear the criticism/questioning with an open mind and perhaps rethink? Or become secure in your choice/belief as a result.
It doesn't make sense.