Because I don't actually think this sounds very scientific.
Leaving aside the mythology part, the conch shell's significance can also be corroborated by science. If you try holding a shankha near your ear, the sound of the gently humming ocean can be heard. This is actually the natural vibration or cosmic energy of the Earth which gets magnified on entering the conch shell.
The vibrations from these conch shells can overpower evil forces from the Earth and at the same time also clear environmental pollution including healing the hole in the ozone layer which causes global warming. According to science, the blowing of a conch shell enhances the positive psychological vibrations such as courage, determination, hope, optimism, willpower, etc. in the blower as well as those around him.