Yeah. 'Suicide plug' Is a misnomer. Should be 'homicide plug.'
The danger isn't plugging both ends into the same circuit. The danger is when there's a downed power line, somebody plugs a generator into their outlet to power their own house. The genny backfills the line, so this line that everybody thinks is dead is suddenly live. All of a sudden the poor lineman who is trying to fix it a mile downline gets electrocuted while standing on top of a 30' ladder.
I suspect the but am not sure that the same nothing would happen if you plugged it into a different outlet in the room. Since reason nothing happened here was claimed to be that the connections are all shared, and since outlets are wired from one outlet to the next, they would still share the hot, neutral, and ground.