I can see why. While I'm a fan Ryan Drummond's voice-lines, he sounds like a 90's surfer; which suits him back then. Jason Griffith is basically Sonic growing up and taking consideration as he goes.
It fits him when he gets serious. But when he goes "comedy" mode, it just doesn't sound right. His voice isn't "Playful" like Griffith's was
“Who you callin' nothin”
Lol well that's still a semi-serious line. You kinda have to hear (and see) the differences in Sonic's way of doing things between Griffith and Smith. Griffith's Sonic has more "energy" while Smith's Sonic is more...I dunno, laid back? I kinda liked the "hyper" Sonic