Okay, if you wanna know about good or bad anime, here's the thing:
There is Both Good and Bad Anime.
And there are some animes that many people both love and hate.
For example:
I like K-On:

However, it is also one of the most divided animes of the 21st century.
Some people hate K-On because it lacks a story, can be quite shallow, is an otaku bait, and uses "cuteness" as a selling point.
But some people like K-On because it has character development, good writing, excellent art design and has the best camera angles used in anime.
I like K-On for the latter. And even if some people hated K-On, well fuck them. K-On is slice of life. And slice of life animes rarely break into the mainstream. And thus K-On's popularity is like a culture shock to a generation of anime fans raised on mecha, horror, sci-fi and action stories. And it's my right as a human being to enjoy something that others might not enjoy.
But like i've said, there are animes that some think it sucks, while others think it's good. It's been like that since the dawn of mankind.
And even if the bad and mediocre animes like Pokemon perpetuates the beliefs that "animes are for kids" and "all animes suck", then it's up to the otaku and the average casual anime viewer to change that. If One Piece and Hokuto No Ken taught us anything, it's that we can change how others see us for the better of mankind. And if you met anyone who thinks that all animes are about "tentacle rape", then you must give him or her a copy of either Hokuto No Ken or Cowboy Bebop, because people like that deserve it.
Oh and thanks for checking out Avatar the Last Airbender. Hell yeah, Season 2 is awesome.