I completely respect and support wholeheartedly the desire to seek advice and feedback on commits and I understand that ACK is more about asking for a review though I don't believe mandating it (not that it has been necessarily) is appropriate unless it's actually been demonstrated to be a problem -- I've not ever experienced that) but perhaps it was on this project and I'm just coming on board too late to have seen it. Similarly, I don't see that the desire to keep abreast of, seek feedback for, and review commits as being predicated on sending patches to a list per se.
I view the argument that git supports feature X (eg send-email) therefore it's a good thing, as a somewhat circular one considering many features are in git mostly because that's what the linux kernel developers do as opposed to it being the most effective way to manage this or any other particular project. Git allows me to do many things I would consider bad practice.
I also don't personally feel the need to keep git history clean per se. In fact I actually like seeing commits reverted and the reasons for it. I think one source of history (as opposed to having to dig through a list) is actually a benefit.
All that said, I concede that the weight of support is behind the current process and I don't feel the need to argue for Just Another Process(tm). I'm too old for that but thankfully as yet not too old to change my habits to accommodate :)