The one thing i wanna point out, is they didnt come out at the same time. rust has been available to play as a early access for much longer, ive been playing for almost 5 months. The steam release was what your considering the early access release, which is false. not that it really matters though, it just happened to be one of your opening points.
i agree that Dayz SHOULD be on steam, i always hear people say ooh its all buggy it sucks this and that, but its early access.. people fail to realize that. even with the paragraph of warnings towards it being early access lol.
one point you didnt make that i think is important, is where the games are heading. in regards to rust moreso, like the fact zombies are being removed, thus becoming simply a survival game.
Also, in regards to hacking, both games are bad atm. rust has AB/WH/SH loot through walls and the ability to dupe, while dayz has AB/WH , a maphack, the ability to teliport anywhere on the map, ability to teliport any item from x distance to your feet(basically making it so you dont have to walk to the items lol) hacking shoudlnt be what makes or breaks a sale of a game. honestly i find more teliport hackers in dayz that i do wall looters in rust. but thats just me
Rust has had early access for about a month now, what you're talking about is the closed Alpha with Dutch Auction. Rust got released on Steam five days before DayZ.
At the moment I feel like Rust is a lot more polished and there's a lot more to do then DayZ. In DayZ you spent a hour getting to NW Airfield, get some loot and die to a hacker.