I respectfully think the opposite. Snake's bazooka is awkward to control, atleast with the gamecube controller. On top of that, half of his moves can hurt him. I tend to find it aggrivating to have to keep track of all his mines when I am fighting four opponents.
Easiest to learn how to use is definatley Mario. His moves are the most straight-forward.
1) his short reach. Olimar doesn't reach very far without pikmin, but you gotta be able to fight without them at times in order to survive. short physical reach=screwed.
2)the pikmin moves: it takes time to master every pikmin move perfectly cause each one is affected by the pikmin
3) the pikmin themselves: to really master Olimar you have to know exactly what each pikmin can do, what order there in and the best pikmin for each situation. i may main Olimar but it took me a long time to learn all this stuff.
like for instance, purple is strongest but has the shortest reach and is the rarest to pluck. yellow does little damage but stuns people and goes farthest. white has the weakest offense power and dies in one hit but it does the best damage for the pikmin throw.
4) the stages: you have to know what the ground is made of so you know what areas produce which pikmin best. Olimar not only makes you learn him, but the stages as well.
5) tether recovery: Olimar relies on a tether. right there is a handicap in itself, not to mention it relies on pikmin. you must know how far the pikmin can get you cause a full chain is the longest tether in smash but you won't always have 6 pikmin with you.
although i pretty much mastered every character, the one who took me the longest was jigglypuff, although when you know how to use her effectively, shes a pretty good character and definitley does NOT suck apermario: