Nothing wrong with the animation? Sorry, but that's a matter of factual inaccuracy. The animation was cheap - they reused sequences in every episodes - and, aside from Scooby, it barely moved. It was the 1960s, but stuff like Looney Tunes, Disney Shorts and the original Tom & Jerry shorts were made before then, and they still looked beautiful, so that's no excuse.
And you're right, it often was the person you'd least expect... in fact, it was
always the person you least expected. You could figure out the mysteries just by picking the person who had the least stated reasons for doing the crime.
Saying it had "next-to-nothing" going for it was hyperbolic, you're right - it did strengths. But it still had so many flaws, many of them brought on by Hanna-Barbera themselves that comparisons with, say, Tom & Jerry (by the same people) aren't just uneven - they're unfair, to either show.
(Also, sorry about accusing you of insulting people - I thought you were trying to say the only reason people would dislike SB was because they were too young, but I may have misread your comment.

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