I guess, that's what you get for supporting a file format through the years in a backwards-compatible manner.

But I also believe, that over the time technical debt like this is a huge advantage for the company, because it fences off competitors entering the domain through integration.

Another example is the Adobe PDF spec. In my opinion a thoroughly overdesigned document structure where it's nearly impossible to implement every possible way of positioning an element. Trust me, i've seen alot of differently produced PDFs and it feels like each one of them is a unique snowflake.

The only one who profits is Adobe which provides the only Reader supporting every feature imaginable...