Something would ‘make sense’ if it appears to be correct according to our personal experience. But common sense can be deceiving. Common sense relies on our own experience which has a very limited scope. For a lot of things, our common sense is not a reliable indicator of truth.
Perpetrators of flat-Earth often exploit the shortcoming of our common sense. They would say something like “It looks flat, so it must be flat!” Some of us fell victim to this scheme and would make the conclusion out of a mere hunch in place of more thorough and exhaustive observations.