The thing is, Sonic has piss poor priority. It is in Bowser's advantage to have Sonic charge at him with attacks, because Bowser will outprioritize nearly everytime. Bowser can rack up damage this way then hunt for the KO. Sonic, meanwhile, must rack a huge amount of damage to Bowser to get a reliable kill. If Sonic just keeps going head to head vs. Bowser, it's a losing battle for Sonic. Sonic's largest advantage over Bowser is his speed. Seeing as this speed can't be utilized by blindly dashing in and attacking, Sonic has to wait (or "camp') then use the speed to his advantage one he sees an opening.
This match in particular, Dennis waited to attack while Gimpy knowingly threw out jabs and Ftilt, hoping to hit Sonic out of an approach. If Sonic would have dashed in with about any move, jabs and Ftilt would have hit him out of about anything.
Does it make for a super exciting, action packed match? No. But is it good, solid competitive strategy? You bet.
That out of the way, some solid Bowser play from Gimpy. I like the >B cancel jumps for movement, I'm going to have to start using that more, it seems to help him keep momemtum, rather than landing then rejumping. I can't believe how many Bowsercides you hit. Nice!