And so for the time being "Tax the Rich" strikes me as an untenable demand, beyond the levels we are already failing to tax them at. The IRS is undermanned and technically ill-equipped to pursue the more sophisticated tax returns, and thus can really just handle the relatively simple ones, the ones far less deserving of audits, from what I gather.
It was always an unsustainable demand, but not for those reasons. High incomes necessitate high levels of destruction. Your problem is that you're defining the capitalist economy in terms of the already accrued wealth (dead labour) rather than the right to extract from new wealth set into motion (living labour.) In this sense the frenzied work rhythms of contemporary society have no regard for preserving past, ages old wealth (which would of course be a good thing.)