How would "Twitter" capture that value and not some third-party platform who and offers those filter services? The value and revenue isn't with Twitter then, so then how does Twitter pay bills? Or am I seeing this in a different light than you do?
I'm not saying it was a slam dunk, but a lot of talk about this back in 2007/2008 and there was a palpable excitement about Twitter apps. Within a few years the media-company mindset had taken grasp, the valuations and expectations exploded, and now we have boring old Twitter which is still a damn cool thing in its own right, but which is seen as a failure because of a combination of pedestrian vision and mismanaged expectations.