Waves don’t come from pressure. Pressure comes from constrained waves… constraints prevent oscillatory relations from freely satisfying their phases. Pressure is a local manifestation of the same idea behind gravity. When many interacting modes lock into a persistent configuration, they impose constraints on nearby modes. To us on the inside it looks like curvature and attraction. But the comment section on HN is a bloodsport…
You're also trying to argue against a nonzero number of literal physicists who do this type of thinking for a living.