and do nothing whatsoever to exclude the people that some would like excluded.
It would do something about the people we want to exclude, that was my point/intention anyway: there are limits to custom hardware optimization where it becomes just too expensive and you're better off buying or making a faster CPU. Intel is a target you're chasing at the speed of Moore's law. Particularly if the algorithm is changing every 6 months in interesting and novel ways. Imagine someone come to you with a mountain of money and says build me this custom CPU in 3 months (so there's three months left to start mining). Maybe you cant do it in time to repay the investment. Maybe you cant do it in the timeframe with any amount of money. Even all of it - there are complexity and science limits for hw gurus and chip fab people etc.
You are assuming that the investment must be repaid in terms that you understand. Maybe someone is rich and just wants to mess with the network. It seems unwise to make ourselves vulnerable to that sort of thing merely because we wouldn't take advantage of it ourselves.