As a kid I tuned in to the Peanuts animated specials to see Snoopy doing some ridiculously undoglike things, like flying a plane or preparing a Thanksgiving meal, and he definitely stole the show away from Charlie Brown and the rest of the Peanuts gang.
However, Peanuts purists saw Snoopy as the dog who singlehandedly sank the strip.
Peanuts was a much more serious strip to begin with, dealing with the trials and tribulations faced by children and then Charles Schulz started using the Peanuts kids as a mouthpiece for bigger, more adult (and more American) issues.
Then along came Snoopy to silly the whole thing up, which is ironic considering he's had some of the saddest moments in the animated specials (remember Snoopy, Come Home?)
Kevin Wong of Kotaku isn't afraid to share what might be an unpopular opinion about Snoopy in his article How Snoopy Killed Peanuts, give it a read and see if you agree.