> But strangely politicians generally aren't pushing for targeted corrections to reduce those loopholes
You are just not paying attention enough. They do talk about loopholes, and push to close them during the legislative process.
They just don't talk about the loopholes details a lot because you don't get elected by talking about technical details in the tax code: “Force the tax realization of gains at some rate which then adjusts the cost basis when assets are encumbered by loans or as collateral” isn't a slogan that makes you win an election.
