I don't understand what makes Sonic disliked (i ask because i've seen a lot of dislike recently). I can understand he's annoying to fight against but he controls great and can be easily read when he's in the wrong hands. Im a sonic main, and the only reason i dont like sonic is because he's a too predictable (Spin Dash the crap outta anything that moves), but other than that, he's a great character that just knows how to mess you up.
I was just wondering if it was anything beyond a john.... :3
First and foremost, he is annoying to fight against. The spindash is difficult to punish and easy to spam. Often, Sonic ends up behind you on shield, and if you anticipate him, he'l just up and throw a spring in your face. Even bad, spammy Sonics can require some patience to finally corner and attack. Sonic is a threat from anywhere on the stage, whether you are airborne or grounded, and his spindash can and often is delayed indefinitely to create these stupid mexican standoffs where whoever gives up first loses (Like, I did an inhale against a sonic one time anticipating a spindash, and he just sat there for 2 minutes waiting for me to drop inhale so he could release and smack me). Most characters with moves like this have limits on how long they can delay (think Pikachu/Luigi's headbash, or Jigglypuff's rollout).
As a spectator, a lot of his moves look similar. Spindash, homing attack, nair, uair and a few others I'm surely forgetting -- all amount to rolling up in a ball and bashing people. And it's just not fun to watch for 3 minutes as sonic repeatedly attacks somebody's shield before running away. Yeah, top players can handle it, but that doesn't make it fun to watch, nor does it make him fun to fight for casuals.