Given that every language is different, this is basically reasoning by analogy. Sometimes analogies are useful for explaining things, but they're not a reliable way of determining what will definitely work.
Reasoning by analogy in a sneering way doesn't make it work better.
Programming languages differ, yes, but not so much that they face completely different design decisions. Also, it's not "reasoning by analogy", it's learning from others.
In fact, why stop at generics? Why not go back and question structured programming? Or strong typing? Because structured programming and strong typing has proven to be extremely useful. Same as generics in statically typed languages.
Maybe reasoning by analogy and learning from others are about the same thing?
How much you should rely on others' experience, and when you should consider it a positive example versus something to learn from by avoiding, is going to be a judgement call.
Reasoning by analogy in a sneering way doesn't make it work better.