Not to mention he's pretty unimportant in the grand scheme of things...
Oh boy. Warning here: You guys asked for this.
Rant starts HERE:
I see where you're getting at, but outside of the Slime from Dragon Quest, no other Square Enix character has the same ties to Nintendo, and symbolism of company relations.
And Geno debuted almost single handedly the concept of Stars as an important source and symbol of power and wisdom (where's the Starforce of Courage?) that theyso eloquently portray in games such as Galaxy 1 and 2 and Paper Mario, to name a few.
Geno also has moveset potential that tops King K. Rool in terms of sheer possibilities. Detachable rocket arms, pellet pistol fingers, Rapid fire pellet arms, a few punch and kick moves, potential for controlled explosions similar to Mario's Forward Smash. And that's just a few A move ideas! The Geno Whirl, Beam, Boost, etc. could be implemented as Specials and the Final Smash, this stuff writes itself down.
And despite his Square status, like Layton, he's a Nintendo character at heart. Not only has Sakurai acknowledged him on the Brawl and Melee poll, but along with Ridley, Geno was one of the only characters in the Top 10 of Brawls results not to be included.
...Whew, it's getting late. I'm gonna go grab a Pepsi or something.