Companies like MapBox, Stamen, MapQuest, and Bing, who have OSM layers, have an incentive to improve OSM data because it makes them competitive with Google; it

Companies like MapBox, Stamen, MapQuest, and Bing, who have OSM layers, have an incentive to improve OSM data because it makes them competitive with Google; it eliminates the massive fixed/sunk cost of creating proprietary data and redirects the game into how you can use/distribute/mainstream that data. The business models for that are fairly clear; charging for services based on the data.