Neither one has a cool sounding name. Neither one is very articulate. Neither one has much value after age 8.
Although, "Bugs Bunny" sounds more masculine than "Mickey Mouse". Bugs Bunny gets more "likable" points from [real] ladies. Bugs Bunny shows a little more style. (He eats a carrot like Bugsy Segal would smoke a cigar. Mickey doesn't nothing but laugh stupidly.)
Bugs has better catchphrases: "Eh, What's up, Doc?", "Of course you realize this means war!", "Shhhhhhhh! I'm about to defy you.", "I know this defies the law of gravity, but I never studied law!" and my favorite one: "I knew I shoulda taken that left turn at Albuquerque."
And of course, let's consider real world realities. If they were real: what boy age 8-15 would want an all-black, feminine-acting male mouse that doesn't eat cheese vs. a superfly, jive-talking, horny-ass jackrabbit that bones more nookie than Ron Jeremy, Peter North, & Sean Michaels put together?
Well, like Bugs would say: "Don't take life too seriously. You'll never get out alive."