StarCraft is the kind of game that is very easy to learn, but it takes a lifetime to master.

I thought that at first too, but since this graph only views time spent playing vs required skill and there is no guarantee in starcraft that your skill will improve. Some people have over 5k games played and are still bronze, whereas in WoW as you level up the encounters (suposedly) become harder. So I think this might be rightish...

You good sir, don't know wow. Wow isn't a game about leveling up, wow is a game that begins at max level.