Kirby writes -
I understand your side of it though: having them be there would encourage earlier, deeper investigation of the whole topic, and remind the user that a=b does *not* necessarily get that job done.
Actually my point is slightly, but importantly, different than that. The investigation will help the user understand what a=b means. By helping them undertand what a=b doesn't mean. One can argue whether facility with copy is or is not a core concept. I don't think one can argue the same as to a=b.
Guido's school of thought says 'these are power tools that need to be on a higher shelf, so the casual tinkerer won't abuse them if you're not ready to tackle importing, you're not ready to start copying, let alone >deepcopying.'
Guido's express it exactly as "copy() nor deepcopy() is a built-in, because it is a potentially expensive operation, and I feel that its presence as a built-in would cause beginning and intermediate programmers to overuse it." Premature optimization, perhaps? Art