Are Enterprises so lazy to build an API around their data models? I would like to see a detailed comparison of the framework API's(say in django, Tastypie) wi

Are Enterprises so lazy to build an API around their data models? I would like to see a detailed comparison of the framework API's(say in django, Tastypie) with 3rd party managed API's. Its a great read to see the pros and cons in this context.