Really? What about ticketing systems? Certainly when I add a bug or a feature to a ticketing system, it isn't just as difficult as fixing that bug or feature.
The difference being the people working on the ticketing system already have domain knowledge as well as knowledge of the system you are reporting a bug on.
I'm not sure that's the only difference. I'm pretty sure I could walk into many companies and read a ticket and be able to execute without ever having worked on their project before.