Unless there was a poll where one of the answers was "There were too many options, and so I went to play Doom", this is ENTIRELY made up.
The actual text was more like, they looked back at why System Shock had a cult following at best while DOOM buried its developers under sacks of money. And one of the things they found out after the fact (from focus groups? Message boards? Employees at game stores where SS was returned? I don't know) was that, aside from the innate unfriendliness of the user interface, new players tended to be overwhelmed by the very first screen after the intro and not want to play the rest of the game. Too many buttons, tooltips, indicators, etc., with very little indication on what exactly you were supposed to do.
System Shock 2 isn't exactly a stupid game, but choosing your path and the first few minutes at the beginning are a lot easier to jump into than what SS1 threw at the player.