There is absolutely no reason to seize coins which haven't been used in a "while". It is theft. Pure and simple and worse it isn't even necessary.
While I agree completely on your position and explanation (every quantity of money is sufficient and perfectly functional for a good economy), I do not agree that this can be considered "theft":
- refresh the deposity every 10 years (or every 1 million blocks, or whatever it is) is simlple to do by hand and completely automatable, so without any risk of "theft"
- reclaim of lost bitcoins must be made from miners, and so it needs a lot of work for it, and this gives them incentive to mine. So this enables to have less transaction fees.
It doesn't matter how easy it is to avoid theft, taking/confiscating property without due process is theft.
You have no RIGHT to the property of others. Period. If someone makes a deterministic wallet based on a passphrase and then say gets sent to prison for 30 years you should have a right to their personal property because they didn't use it?
Confiscation of property without due process is theft. I don't care if it is 1 year or 10,000 years. Worse it is theft that isn't necessary. Users should have confidence that coins they acquire are theirs and theirs alone without exception.