You make a good point numbsafari, though I disagree with your suggestion that schools will end up paying in the long run. Fundamentally, this is true, but I would add that schools will be paying much less than what they are paying now. Integration with 3rd party apps is time consuming and expensive. If a "once and done" option is available, schools will benefit.
The cost savings for developers is also very real. Instead of having to hire full-time integrators to manage each account with variants for each SIS, developers can plug into an API that works with all SISs once and be done.
Finally, we should remember that having access to an API that is not regulated by SIS companies allows for the development of a new generation of edtech that until now, was not possible due to the fact that much of the data is purposely locked away in the SIS. Would Pearson really want parents using something like Edmodo in lieu of their own portal? In the attention economy, it's not in Pearson's interest to enable these types of solutions.
The cost savings for developers is also very real. Instead of having to hire full-time integrators to manage each account with variants for each SIS, developers can plug into an API that works with all SISs once and be done.
Finally, we should remember that having access to an API that is not regulated by SIS companies allows for the development of a new generation of edtech that until now, was not possible due to the fact that much of the data is purposely locked away in the SIS. Would Pearson really want parents using something like Edmodo in lieu of their own portal? In the attention economy, it's not in Pearson's interest to enable these types of solutions.