> you don't say "this person won the 0th place trophy"

I think it would make sense to say it. The reason I don't is that people around me would misunderstand me if I did. (Around some people, it works, though!)

If some told me they got the "0th place trophy", I would take that to be a colorful way of saying they didn't win anything, as 0 means nothing, or the absence of trophies, in this case.

That's just an artefact of being used to a certain way, isn't it? For me, it's about finding fundamental reasons for one convention or another, not about the practicalities.

The reason for not starting at zero for enumeration is that zero means a lack of things to count or list. Therefore, we should start with the one, since that's the first number where we would have reason to enumerate.

Why not say someone won the -1th place trophy? Where does it start?