the basic argument reads to me as "taxing wealth at 100% would be bad policy (for various reasons), therefore taxing wealth (at all) is fundamentally bad policy

the basic argument reads to me as "taxing wealth at 100% would be bad policy (for various reasons), therefore taxing wealth (at all) is fundamentally bad policy". taxing income at 100% would also be bad policy - that fact alone doesn't mean that taxing income (at all) is fundamentally bad policy. I don't find that the post really engages with any more realistic scenario.