It's not usually rudeness, so much as mutual incomprehension. A couple who owned a planing powercruiser came out for a trip on a sailing yacht of similar size during last year's "Big Blue - try watersports day" and had a very good chat with the crew. I don't think any of the assembled raggies had appreciated how much noise there was when a powerboat was planing on anything but a millpond.
The powerboaters hadn't appreciated how badly wash can affect a sailing boat, particularly when racing in light winds. Waves may be bigger but they are regular and predictable.
PS. I like both the Doulas Bader/Fokker joke and Gerrard Hoffnung's "Letter from a Golder's Green bricklayer to his employer" monologue. Age has not withered either joke.