Comment by rahoulb

As other posters have said - capitalism.

But also privacy - it would be amazing to just be able to connect to any app or service you want, interact and react to stuff that's happening _over there_.

However, do you want any old app or service connecting to _your_ data, siphoning it and selling it on (and, at best, burying their use of your data in a huge terms of service document that no-one reads, at worst, lying about what they do with that information)? So you have to add access controls that are either intrusive and/or complex, or, more likely, just ignored. Then the provider gets sued for leaking data and we're in a situation where no-one dares open up.