I'm familiar with the comment, but I believe that the idea that trained musicians were unfamiliar with modal scales in Sharp's day is nonsense. Maybe the commentator meant that many couldn't identify them by name if asked.

My understanding is that trained musicians knew exactly what "modal" meant and more or less what the scales sounded like from the study of music history, but thought they were "primitive" and thus largely unsuitable for "modern" music.

But the question is relatively moot. There are few modal shanties.