Boiling water in a pot without the lid on is a beginners mistake. The fix is easy, obvious and the gains are significant. Claiming that it eventually works anyway is setting a low standard.
With code the factor can often be several magnitudes larger than the example above. Like using O(N*N) where O(N) is the norm, spawning a thread for every function call, doing rpc for things that should be local, and so on.
These things are bad practices and it’s ok to call them mistakes. Beginners will make mistakes and that is acceptable. Everybody learns.
