For a long time Twitter apps were developed simply to enjoy the Twitter hype rather than any financial gain. For some reason Mainstream media adopted Twitter as

For a long time Twitter apps were developed simply to enjoy the Twitter hype rather than any financial gain. For some reason Mainstream media adopted Twitter as the invention of the century, so developing a unique Twitter app was a way to get linked to from some gushing NYT article. Now that Twitter is less of a novelty, and the chances of making any money off it are not impressive, it's not such an attractive prospect, regardless of Twitter's own actions.