You are correct, but it's far better to have expensive-by-default but safe operations vs the counterintuitive mess you end up with when comparing references by

You are correct, but it's far better to have expensive-by-default but safe operations vs the counterintuitive mess you end up with when comparing references by default. The point is that you need to counter human nature, which is to not do work you can get away with not doing. If the worst case result of not doing the work (i.e. not creating an equals method) is slow performance, that's better than getting incorrect results. You'll have a much harder time designing a useable language if your understanding of human psychology is poor. Besides, in 90% of cases, you won't have potentially recursive types, and so a smart compiler can optimize for this when generating a default equals method. In fact, many cases could just degenerate into a memcmp.