[kqr]

That depends entirely on whether you add the question as a formality or if you are genuinely interested in why the other person might disagree.

[graftak]

To me ’…don’t you agree?’ is the sort of rhetoric that parents use to make their kids internalise their beliefs.

If someone disagrees I expect them to speak up, if they’re not so inclined I’m interested to know why, so we can address/resolve that and move on.

[Kaze404]

The comment says "do you agree?", not "don't you agree?". I agree that the latter sounds condescending, but the former sounds reasonable to me.