all gates (including NAND and NOR gates) can be made with the AND and NOT gates but its much more complicated for no reason if you went the other way meaning starting with the AND gate and the NOT gate makes it both simple and diverse.
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How is it complicated? It's no more complicated than making OR from AND and NOT gates. Look, the way I see it is there's two potential goals here, start simple for beginners (in which case it makes sense to also include OR, the other basic gate) or build your way up from nothing (in which case building everything from NAND or NOR would be better).