The fact that that article compared Nero to Raiden invalidates it.
Raiden was a massive angster that really put off fans of the first game, who were used to the grizzled determination of Solid Snake.
Nero wasn't anywhere close to "whiny." The only time where he DOES get "whiny" and "serious" is when his girlfriend is kidnapped. Dante did the EXACT SAME THING in the first game after Mundus pulled a You Have Failed Me on Griffon.
Nero was still wisecracking, arrogant, and a badass through and through. Granted, he wasn't Dante, but he wasn't exactly a BAD addition to the series. --- "20 bucks says none of you dumb white people can kill me!" - Eric Nally