I have to back you on this… There are elo systems which go down to 100 elo and still have a significant number of players who are at the floor. Having seen a few of these games, those players are truly terrible but will still occasionally do something good, because they are actually trying to win. I expect random to be somewhere around −300 or so when not tested in strange circumstances which break the modelling assumptions (the source described had multiple deterministic engines playing in the same tournament, aside from the concerns you mentioned in the other thread).
I have to back you on this… There are elo systems which go down to 100 elo and still have a significant number of players who are at the floor. Having seen a few of these games, those players are truly terrible but will still occasionally do something good, because they are actually trying to win. I expect random to be somewhere around −300 or so when not tested in strange circumstances which break the modelling assumptions (the source described had multiple deterministic engines playing in the same tournament, aside from the concerns you mentioned in the other thread).