[tempodox]

I suppose, that's a question of culture. If truth is something that can be approximated or found, then having my beliefs shaken is something to be welcomed if it can bring me “closer to the truth” (whatever that may be). If, however, truth is present a priori, and my beliefs just a path to it, then having them shaken would remove me further from that assumed truth, and that would indeed be “rude”.

If your quoted sentence were true unqualifiedly, then science could not exist. Science is shaking-your-beliefs-as-a-way-of-life. Every single day.

[Delmania]

As has been pointed out many times, that's the difference between science and religion. From day, scientists are trained to understand their beliefs and understandings must be based on the evidence before them, and that if the evidence no longer supports the belief, a new belief must be adopted. Religion is based on the idea that the belief is right, and everything else must adopt to it, regardless of the evidence.