I'm not seeing why larger MACHOs have to emit light (I'm tempted to reference black holes again, but where they fit into the classification of normal/normal dark/exotic dark matter seems ambiguous). Probably just my ignorance showing again, but since stars produce all the heavy nuclei large aggregates of those nuclei, either as nebulae or non-luminous masses, seem viable, especially at the edge of the galaxy. As I understand it, stellar formation is thought to produce energy levels that preclude anything more complex than hydrogen and helium, but if heavier nuclei can exist within old stars it seems like they ought to be able to mass without the force of their compaction reducing them to hydrogen nuclei and ultimately igniting a star. Eliminating MACHOs from the Milky Ways perimeter through gravitational lensing eliminates any other matter as well, but I don't see why it eliminates MACHOs in other locations where gravitational lensing shows dark matter.

You lost me here, sorry. If there's enough gravitational lensing (our main evidence of dark matter, right?) to account for the Milky Ways rotation how can a there be a LACK of such lensing that rules out non-luminous MACHOs? Wouldn't gravitational lensing that rules out one rule out the other?

It partly stems from that, unquestionably, but it mainly stems from knowing science has an impressive track record of doing that kind of thing. It's tempting to portray Galileos stand against Rome as science vs. religion, but the fact is there were plenty of well established members of the scientific community on the other side of that argument. It was not so much science vs. religion as revolutionary science vs. establishment science; establishment religion just had a vested interest in taking the latters side. Just recently I was reading about Max Planck being told when he started grad school that he was basically wasting his time because physics was a finished field with only a few known minor details left to flesh out fully, and that mindset made quantum mechanics very controversial for some time. Knowing that "quintessence" long flourished as an explanation for light behaving as both wave and particle in the days before duality was conceived makes it natural to worry it might be happpening again (especially, once again, when the same term has been revived with a new application). As you've suggested, I may guilty of my own charge in clinging to non-exotic dark matter, but I'm trying not to get married to either novel or established physics, but stay focused on accurate explanations regardless of source. There's ample precedent to fear such overcommitment; again, I accept your statement that it's not happening because you undeniably have more knowlege on which to judge. That said, I hope you don't mean it CAN'T happen, because expanding knowledge encourages rather than discouraging it.

I'm not ignoring or marginalizing it, but it still seems inconclusive. If it rules out normal dark matter, which seems to be the case, I accept that correction and apologize for unfounded objections. As I understand the evidence you've presented, however, the case AGAINST normal dark matter is quite strong but the case FOR exotic dark matter much less so.