Comment by AshleysBrain

As cool as copilot may look, it does seem like a fundamental problem could be: if people widely use bad practices, and only a small amount of code uses good practices, an AI model will probably suggest bad practices. The AI doesn't know what's good practice, just what people tend to do. Similarly it will probably tend to suggest legacy/outdated code, since less code will be using the newer modern alternatives. I'd guess that's what happened here, and it's a bit embarrassing that their headline marketing demo does exactly that. It may be difficult to mitigate as well, as this will be rife throughout the training data.