I initiated this post to deter developers from taking this route if what I am saying makes sense, and may I ask if somebody knows if any coin can be burned?
I would think that any "actual" coin would be burnable. If you cannot create an address with an intractable key (either never existing or demonstrably destroyed) then this would logically imply a lack of security of coins in addresses to begin with.
Also, I personally think that what you are saying does make a lot of sense. However, I have never actually understood there to be a legitimate need for any "turn in" process anyway. It would seem to me that any "V2" of a coin could just be seeded from the chain state of its predecessor in its genesis. This fact makes me suspect of the practice.
In fact, I'd like to generalize this statement and say that I have never actually understood there to be a legitimate need for any centralized and manual intervention by developers on anything related to balance holdings of users. This encompasses things like manually disbursed mining subsidies, features/aspects of some hosted wallet services, many IPO/ICO mechanisms, certain types of hard forks and rollbacks, etc. My understanding is that crypto-currency was devised specifically to avoid these kinds of practices found in traditional fiat finance. I consider their use to be representative of a significant failure of a crypto-currency to meet first principle goals, in any case.
Any opportunity for a developer (or anyone) to adjust the apportionment of stake held is an opportunity for them to increase their own relative holdings.
