What did he propose in alternative?
There are a few options to choose from...

Gronan and/or Greg can certainly comment on this better than I, but I seem to remember reading somewhere that Dave liked to use Constitution (or health, or whatever it was called) in place of hit points.

In other words, the "hit point" was a fabrication from Chainmail that took a number of hits (e.g. "hit dice") and converted them into a smaller base unit which was more random, so that a successful attack wouldn't do one hit but a random amount of damage.

I seem to recall that Dave used percentile dice for attributes and that the actual stat represented damage that could be taken, rather than adding an additional "hit point" statistic.

Again, there are probably others more qualified to answer than I am -- I may have dreamed this whole thing up. :P

Interesting. I had thought to do something similar for a Blackmoor-inspired Castles & Crusades game ala Decipher's Lord of the Rings RPG by using a player's Constitution to represent each block of hit points (4 blocks of human-sized targets with progressively higher penalties the more hits you take). The idea is to do away with class-based Hit Dice but also to make it more Heroic Fantasy than regular D&D since you're supposed to mow down bad guys by the bushel!