From reading your comment, it is quite obvious to tell that you do not have knowledge of the rules, or TTT at all, which I didn't expect coming from you, considering your comments are usually well-written.

The flaw of your argument, as Nepgear mentioned, comes from the fact that you're comparing a chaotic clusterfuck of a "murder-game", Among Us, to a very well-refined and old Garry's Mod gamemode, TTT, which has many, many different situations, rules and laws, one of which is the fact that walking over an unidentified body gets you shot.

Among Us is a party game without any real rules, its focus being trying to figure out what the hell is going on and it is vastly different from TTT. Of course there will be people that stand on a corpse, not reporting it, ending up in them getting thrown out, probably upsetting them (and instantly leaving, like everyone does). Well, why does this happen? Because they're new, and there's literally no official information about how you're meant to play, as the playstiyle comes from the playerbase itself from unspoken rules.

TTT, on the other hand, has pages of rules, information threads and so on. It is a completely invalid and weak argument that "a new player might pass an unidentified body without knowing they'll get killed for it", as the very first thing you should do when joining a gamemode/server you're unfamiliar with (I'm sure this is known to be true globally), is read the rules. Even if they are completely new to Garry's Mod and have no idea about how servers work etc, the server constantly reminds players in the text chat about the rules, which they can access via "!rules". Doing so would have given them plenty of insight what gets them KOSed and what doesn't. It is, indeed, the player's fault if they fail to do a very basic and simple action, which is identifying bodies, therefore there is no reason to change a vital rule because of new players that don't read rules. Be sure to play on the server sometime, get familiar with everything and you'll know how much changing this rule would damage and straight up break TTT.

Do not be insulted, but this is, by far, the worst argument I've heard about why not identifying unidentified bodies should no longer be KOSable.