Anime has something different than TV shows that most people like. The art style is good and vibrant, and the shows range from every genre you can think of. They are just way more entertaining than normal shows.
Because it's entertaining. The only difference with anime is that there are much more creative shows to pick from rather than an overused idea which tv shows are mostly. What age? If you do any programming, what age did you learn to make a first program?
I don't know what insecurities have to do with it, its just a form of media. I think western people are drawn to it just because it's different and offers new tropes and story-lines that they're not used to seeing. It shouldn't have any more to do with insecurities than video games or TV or movies do.