While looking for a decent in-browser Markdown editor that could be connected to MS One drive, I noticed an interesting thing. A few fairly popular editors have possibility to work with files stored on either Dropbox or on Google drive, but not on MS One drive. Examples: Writebox, Stackedit, Dillinger. The last one claims to have support for One drive amongst other drives but it does not work, I checked it (later I discovered this non-closed ticket that had been raised... five years ago!).
Why is this? What is so special about One drive API compare to those of others. Clearly, the APIs are different, but was MS One drive API designed in such a way to make it difficult for indie developer software to connect to One drive? If so, which purpose does this unnatural limitation serve?