If you can burn or lock coins for arbitrary reasons, then you have proven that you can manipulate the ledger, after which it will never be long until censorship rears its regular head.
Irrelevant arguments here because we are not talking about some "arbitrary reasons" we are talking about a serious one that would make the very thing that made bitcoin secure becoming obsolete.
It's not all about price either, in fact not preventing old UTXOs from being spent would be against the fundamentals of bitcoin where your coins are only yours to spend not everyone's.