Totally agree with the original request. This kind of data is far better managed by sqlite in a handful of relational tables. You haven't to reinvent the wheel for a "better API" - simply use SQL. Far far better than JSON files in a directory structure. Some TV sets also export the channel list as sqlite DB file. For these you do not even need a special editor for tweaking. One of the many sqlite clients will do the job (even as browser add-on).
Just had to modify the generated icon path of some channels. So I had to do it very low level (bash, grep, sed). With sqlite a single "update" would have it done - even transactional!