> decision reducing the market cap of companies as an attack on the retirement portfolios

Any decision that results in a long term net loss across the entire public economy? Yes.

That's something that hurts a lot of people and that hurt should be carefully weighed against whatever the assumed benefit is. Sometimes that's worth it, sometimes it's not

But it's never OK to just hand wave with "well I don't care about that class of people so screw them"

And let's not move the goalposts. OPs proposal was a corporate breakup of massive scale, not a minimum lumens requirement.