Plastic is impervious to magic?

Season 2 Episode 6.

Not only is that stupid, but it is a lie. There are many instances in the show (throughout all the seasons, even season 1) where magic is successfully used on plastic objects.

This show is so full of errors. What is the target audience of this show? People with an IQ level in the single digits?

The more I watch this show the more it just seems like epic fail to me. The plot-holes, continuity errors, goofs, mistakes, errors, and unresolved plot points just keep piling up the longer the show goes on. How the heck did this show win any awards? Didn't people notice the blatant enormous mistakes all over the place everywhere in the show? I'm beginning to think the writers were on drugs while writing the episodes for this show.