Why do most fans portray Sora as being super dumb in fanfics,fan videos and/or fanart?

Because he is a kid, hes naive, and is still learning about the HUGE amount of stuff going on. He's not quite the brightest person in the series...especially in the segundo game.

Becuz ppl are idiots.
...Yeah thats pretty much it XD

I wouldn't say that people portray him as dumb, I would say it's más like he's just a young and naive kid. He's still growing up, he's kinda immature and he is always so cheerful, which could make him seem like not the brightest dude in KH, but I wouldn't say that he's dumb.

Hes not really dumb but with everything going on around him he cant focus on the simpler things.

I'm not gonna be portraying him dumbin my Fanfic. Donald and Goofy though......total stupidity without my help.XD as for why other people do portray him as dumb...its not dumb so much as naive, and trying to have some fun. he kid.... we must remember this...(of course in my fan fic he's an adult so.....really its makes no sense for me to even say I won't portray him as stupid in my fan fic)