While this might be good for large companies, it's dangerous for startups. Someone else has complete control over the infrastructure of your business and it not only makes it difficult for you to make simple changes that could save you money, but it's very expensive compared to traditional servers that you run yourself.
I run all of my own servers and it would cost me 10X to run it on AWS.
Too many startups outsource their infrastructure or create a business that relies completely on another business platform like Twitter/Facebook and then get squashed when things change or the platform doesn't want you to have too much power.
The book called 'Hatching Twitter' shows exactly this mindset: 3rd party API users were cut-off because the execs at Twitter realized that only a few of the 3rd party apps together had enough of a user base to compete with Twitter.
Which is why all of these services follow the same handbook: have generous access to the API, after this brings in and builds the user base, Cut-off access and severely limit the API (to prevent users from leaving).
One other step is charging so much money for the API access that it bankrupts most of these businesses and then launch a competing app.