[jka]

That's a useful perspective: let's say 3% of a service's userbase really loves an obscure feature (they rate it highly), but at the scale of the business, it doesn't make sense to support that feature within the core product.

That seems like an indicator that there could be a viable business around that single feature. But can that business exist if the larger company's product doesn't provide interfaces that allow peer products to interoperate?

(I wouldn't call those "plugins" or "API integrations" -- those make it seem like there is one "primary" product and one vendor who creates a smaller, secondary component. in the Unix philosophy, any two tools can combine without the need for any clear priority of roles)