well as i mentioned above the whole idea behind monticello goes hand in hand with the idea of having to program a/in a vm. you may like the vm/object structure more than a file based structure, but ymmv.
not to mention that when we were evaluating squeak a year or so back git was nothing more than a half assed gsoc project.
but even so, the fact that you can pipe anything into git one way or another doesn't change the fact that they are conceptually different, but if it does, feel free to correct me.
I thought the frontrunner to git was bitkeeper, which as all the other versioning systems grew out of the experiences from DVS, which i guess refers to what you said, but bitkeeper was built long before monticello.
how does git backend for monticello work? does it turn objects into text so they can be versioned in git? if so that's exactly what dvs was doing for cvs.