Maybe they were more dynamic than current shows, but they're not exactly what I would call good either. They all look fairly mundane to me.
Some would, some wouldn't. In those cases, I say better writing would be the most important improvement they could use, but better animation wouldn't hurt either.
While that can be true, it doesn't really explain situations like how one guy on Newgrounds can make more appealing flash-animation by himself than an actual team of animators who are being paid. Or at least, make you wonder what that one person could do if they had some financial backing and a team to help him.
I never really get the whole 'lower your standards' thing. If some shows already prove what the medium is capable of, then there's no real excuse not to expect at least an attempt to live up to that level of quality from that point on.