It's not the same thing. Kobe carried the Lakers much more than Nash carried the Suns that year.
Nash is interesting. The first MVP he won, there were a lot of factors.
Is was his first year on the Suns and there was a big turn around. So that gets everyone's attention.
I also think the Suns' style had a lot to do with that. At that time, scoring in the NBA was down and, at times, pretty ugly outside of Lakers vs. Kings.
The Suns' style that year, and the next few, was a return to 80s style. I think a lot of people liked that.
The Suns can't play that style without Nash. Was Nash better than Kobe, no. But like we've talked about in a previous thread - it's not about just being better.
Nash's second MVP was won on another factor. The fact that Nash led the Suns to 54 wins with Amare being out for all but 3 games. That won him the MVP.
Had Amare been healthy and they won 60, Nash would not have won MVP. But keeping the Suns at the top of the West without the 2nd best, or best, player was the reason Nash won.