A good definition of 'science' is simply knowledge obtained via observation. Then 'pseudoscience' is the 'knowledge' that is claimed to be science but which actualy is not. The problem is that what constitute 'enough evidence' is actually subjective. To some pple, the school teaching and the satelite photograph of earth is not enough evidence that the earth is round. So to them, 'round earth theory' is pseudoscience!
A good attitude of a scientist or any other 'truth seeker' should not lead him to ridicul an idea that might be true after all. Yet 'pseudoscience' label is just that by nature! In the bible, it was stated that 'the earth is hanged upon nothing' during a time when no one could prove it! But if we booted the 'round earth hypothesis' in the 'pseudoscience' folder just because someone claimed it as fact but he could not prove it, then any attempt to verify it would not be respectable and this would retard knowledge.