I'd say because they are different, and people want to know how they work. I'm very happy with how Olimar turned out (And how I predicted more than half of how the Pikmin will work if anyone read the thread I posted about their uniqueness yesterday)
I see indeed that he will require alot of strategy, but it will be a hell of alot of fun to learn. I look forward to it. Also, one question this brings up, if you have 6 Pikmin beating down an enemy while they are latched on, does it weigh them down? I also forsee a major Olimar KO possibility. Throw white and red Pikmin on and let them rack up damage on the enemy, then grab the pruple while theyre still covered in Pikmin, and he'll slam right into them, Koing them almost instantly.
That. will. be. awesome.