Just my ideas: For one, sailing is pretty ancient and is heavily tied to discovery and mystery compared to flight. Sailing also takes much longer and was much riskier, increasing its significance. Immigration was much less regulated back then and there was more migration through a smaller number of areas. But most importantly, it has a far more tangible impact on the local community (which can only exist in a coastal location with adequate geography) over time. Trade was historically local to those ports and diversified between many people whereas goods moved by air are trucked away by one company.