Of course there's a KG factor. That doesn't mean people are wearing green glasses. I have a hard time believing that there's a fan of the NBA who doesn't believe there's a KG factor, after watching how he instantly infused this team with energy, and watching his passion and intensity.
With Kobe, what's a neutral or fair evaluation? I think he's an amazing individual talent who has an amazing drive, but who no longer can consistently win games on his own. Heck, he's never been able to consistently win games on his own. Recently, his teams have performed poorly when he has "gone off" on scoring binges. He needs big contributions from his supporting cast.
What part of the "the achilles will slow him down" argument don't you buy? Guys at his age who experience major injuries are generally going to show some decline, at least initially.
I'm pretty sure fans know there is a "KG Factor" but the thing is they probably don't overrate it like the people here do. Anyways last time I checked KG led his team to a 41-40 regular season and a first round exit. (I realize you are going to point out what happen to Kobe, but now he doesn't have to deal with Dwight and has a team that plays to his strengths.)
That's why Kobe has guys like Jack, Millsap, etc. (I would like to point out that Jack didn't choke in the playoffs, he averaged 17.2 ppg and .506 FG%.)
Ok let's say he does show some decline initially he will be back at full strength come playoffs though.