I share the same opinion. Its limit make it useful only for a very small set of use cases.

It's being used a lot for code documentation, but MD is bad fit for documentation. Good documentation requires a lot more formatting and cross-referencing than you'd think. Every language I'm using that has been using MD (for embedded and online docs) added extensions, resulting in more fragmentation.

So in general I switch between 3-4 differently-flavoured markdowns constantly. The extended syntax used by various projects sucks. Where did the simplicity of MD go? It reads poorly when unformatted, which is how I read it 99.9% of the time.

I gravitate more towards RST as it's a bit more widely used, but also agree about AsciiDoc.