Summary:

Wind charges don't affect minecarts and boats as much as other entities/players.

Shown here: https://youtu.be/E9waQavwM7I

Steps to reproduce:

1. Build a setup similar to that in the video (4 dispensers with wind charges around a pressure plate)
2. Drop a minecart into the contraption
3. Jump into the contraption yourself

Observed Behavior:

Minecarts and boats barely get off the ground (3-5 blocks), while players and other mobs launch high into the air (40-50 blocks).

Expected Behavior:

Vehicles and other entities to be launch at roughly the same heights.