Those articles point more towards Nokia's support. I am more curious if there is something wrong with the actual OS.

That depends on you viewpoint. The OS itself is technically good (as in significantly better designed than android and friends).

On the other hand, Symbian has some generally good design assumptions (for example client-server division of almost anything) that are hard for programmers that come from other platforms/just don't care and thus it's architecture is often hacked around, which sadly includes many applications written by Nokia itself.