Yeah, it creates an adversarial relationship which isn't particularly pleasant. E.g. they have no incentive to build functionality to help integrate, nor do they have the same incentive to provide stable integration points. In fact, it sounds like stable integration points are borderline actively dissuaded as they would limit agility of Signal and relegate it to irrelevance.

As much as I disagree with the underlying values, I haven't carved out 40 million monthly active users from a crowded space, so maybe it really is the best chance.