It is much more of a complicated situation then you are describing and more than I can articulate.
Simply, to facilitate what you describe would allow a footing for regulators to control Bitcoin
I don't get it. On the other hand, if someone dies (without will and his keys available to his heirs), what to do with his coins which are known to belong to him?
If the individual doesn't prepare for their heirs to receive their coins in the event of
death, then they are lost as Satoshi intended. There is no obligation nor need to
maintain the full 21 million coins. This is not an inflationary system, but dis-inflationary.
Coins being lost forever is not an issue with this type of financial instrument.
You need to understand that the only way to transfer is by the privatekey, you are advocating another way.
A way to get around the privatekey, by using a backdoor. Even if it is programmed and placed into the protocol
through consensus, it would brake Bitcoin fundamentally.
Currently, bitcoins can ONLY move by its associated privatekey signing proof of control.
Your proposal would say that after so much time, forget the privatekey, just move without it.
That is very controversial, IMO.
Again, this can be argued
If there is a way to create money (and bitcoins are also created basically out of thin air, let's be honest here), there should be a way to destroy it. As I understand it, the process of creating new bitcoins doesn't involve private keys, which are used to access or move the money. In this way, we could as well expect that the reverse process (let's call it unmining bitcoins) should be as straightforward
You can not "unmine" the bitcoins without destroying the whole chain from when
those btc where placed within a block.
Very simply, when a miner finds a block and takes the coinbase, it is based on rules.
The rule is, you found the block, now only take 12.5 from the coin jar, if you take
more your block is invalidated. The miners follow this rule or else they lose the block
and its coinbase. When a miner takes the 12.5 coinbase, it is transferred to that miners
btc address and included in that block.
If later you wish to "unmine" certain bitcoins within a certain block,
it would cause that block and all blocks that follow to be invalidated since each block is
built based on all prior blocks being valid and their txs being valid. So if you "unmined"
some bitcoins, you are effectively saying prior work was wrong and destroy all those blocks.
The system relies on and is built upon the rule that no bitcoins can be unmined.
If it is allowed, it would destroy everything up to the point of the unmined bitcoin block.
In theory, all 21 million bitcoins currently exist and were placed by Satoshi to be taken over time.
Miners do not create new coins, they are only grabbing from the pile, and at some point, there is
nothing left to grab.