I think the problem is that people generalize flash with being bad is because a lot of bad shows happen to be in flash, therefore, any show in flash automatically sucks.
Its like, ok...get off your nostalgia kick about how the 90s were great and now everything sucks and watch the darn show and give it an honest chance!
Yeah, if done wrong, flash can look bad. But since when do things need to look immaculate to be entertaining? Thats what I hate about gamers. They cry and whine when a game doesnt look up to par with what a machine is capable of, and completely ignore the quality of the writing/entertainment value. Looks aren't everything.
It's an it depends situation. I mean, I've seen stuff with good writing and hideous animation and stuff with hideous writing and good animation. I've given those examples over and over.
If you look to the first 2-D computer animated show, Dr.Katz the animation is...well... strange. That wasn't even animated so much as they just traced the pictures over and over and made wiggle line movements. Squigglevision. I think they used Director on that (I used Director once way back in 98...). Now they're on a flash no Squiggle basis, and frankly, their shows are better. Home Movies looks better, Word Girl is just amazing...
Now, as I said, it's all just a tool and when used right, it shines... when it's just used for shortcuts, it makes something clumsy looking. The Hanna Barbera analogy is dead on. When the animation and writing are both bad, they tend to make a vile product. I HATE the look of something like Doodlebops Roadshow (again, taking my thoughts aside from the WHY THE CRAP DID THEY NEED TO MAKE IT?!?! factor), but I LOVE stuff like Spliced and Fosters and even Mucha Lucha, and wish that more flash was as fluid as that. Even if there's some stiffness like Archer or Bob's Burgers (which, honestly, I could barely tell it's computer animated, except for some stiffness in joints) that still manages to make the most of the medium. Laziness in any animation is not tolerable. Flash or no flash
I don't want to have to make you sit through an episode of Super Mario 3, but...
http://www.youtube.com/watch?v=qM_IamloWpE
Worst animation I've ever seen on that show, and the animation was sucky throughout. Especially note the "They don't call us SUUUPUH for Nothing....eh huh huh huh" lipsync.