Personally, I wonder if this sort of pushback will drive us towards a more standards-ish way of approaching platforms where it won't be enough to simply provide an API – to get use, you'll need to make it a more standardized API that provides a more standardized sort of data – because only when we have those sorts of standards can we hope of it being safe to develop based on someone else's free API – because I know if I need to, I can substitute in (or combine) some other data source.
Relatedly, Right now, what I think we're seeing is a lack of real competition of direct substitutes. There is nothing exactly substitutable for Twitter quite in the way that products ranging from Heinz Ketchup to the Chevy Malibu face real, direct substitutes, rather than a more abstracted category substitute (i.e. Facebook is similar to Twitter, but it's not a perfect substitute). As such, switching costs are higher and it makes development for a specific platform more risky.