Thats you reading into it what you wish to read into it! Marginal represents unreliable, 9mm ball just doesn't deliver the energy necessary to cause the significant blood pressure spike required to instantly incapacitate, a consequence of it's lack of expansion. It's because of this that 9mm Ball is highly overpenetrative, a specific threat that led the NYPD to finally see the light and adopt the 124 gr Gold Dot as the issue ammunition for their G-19's
No responsible professional in 2010 America would advocate for the adoption of 9mm ball as a duty, or self defense load, as it's just as likely to shoot right through it's intended target and into the innocent behind them, just as it did in NYC. For the very same reason, it's a marginal battlefield performer, it just zips through humans without dumping it's energy, again, because it does not expand.