I know it's just mean to laugh at spelling mistakes. The point of writing is to successfully communicate, and most of the time minor errors don't hamper that. (On the other hand, if it's a setting in which correctness matters--e.g., formal messages or applications for jobs that involve writing them--little oversights might rightly or wrongly communicate subtle secondary information about the incompetence or apathy of the author!) Also, each time I jibe I'm inviting fate to trip me next so as to restore the Universal Balance. Yes, I know there's no such thing, but in case humanity does someday discover it I figure I should be prepared.
However, I draw the line at "genious", because that's just too hilarious and self-referential to pass up. Ha ha ha! I can think of some related quotes: "Judge a pig contest? I don't know, I'm no super-genius... or are I?" by a Mr. Homer Simpson. "Me fail English? That's unpossible." by Ralph Wiggum.