For some perspective: This isn’t just about friendly apps like TPG helping consumers out. If you have an API (or even just turn a blind eye to scraping) and have a popular service, scores of ill-intentioned business people will descend on your business to suck any value they can out of it.
This ranges from all of those StackOverflow scraping websites in your Google search results to companies that want to scrape Facebook for images and personal info to build a database of everyone.