How vein. A signature giving information that nobody could care less about, and being so cheesy as to combine Star Wars, LoD and The Legend of Zelda!!
Firstly, I doubt you're "da bomb" compared probably half the community. Secondly, everybody uses red for the most part. The only people who don't are newcomers who like blue's fast attacks, the people who actually like JediMod and all that other crap (PLUS, Omni, etc), and the people who are smart enough to go to ProMod (the only mod worth playing).
Now, to the topic at hand: You overstate Gohan's power. He's good, but since people at the moment only want power and/or cheap tricks, they go with Buu, Vegeta, and Goku. Goku's got spirit bomb, Vegeta gets Final Flash and Big Bang Attack, and Buu has mouth blast. I'm not saying there's anything wrong with this, I'm just pointing out that's why so few people use Gohan. Occasionally I'll see a Gohan, and he fights well, but most don't use him because he has pretty weak attacks compared to the others, and shield attack can take awhile charge... and is also pretty hard to use effectively.
Oh yeah, and shield attack doesn't block anything when you press secondary and get ready to fire the energy. And you have to hold primary down for it to stay up.... That's probably why you get killed.