Bad Grammar

I'm not sure when I decided that bad grammar was a pet peeve of mine. But, I cannot stand having a conversation with educated people only for them to turn and say "It don't matter." Or something to that effect. I just want to scream "IT"S IT DOESN'T MATTER!" But bad grammar is very widely accepted. From the TV shows stating that they were standing 'on-line' to the commercial where the pretzel is inside an M&Ms. The last time I went to the post office, I was in line. Now, when I'm blogging, I'm online.

I have a lot to pick about the M&Ms commercial: first; an indicates one of something, usually a something beginning with a vowel. An eraser. An analogy. An idiot. So there's grammatical error #1. Next, as mentioned before, an indicates one, therefore, An M&Ms (plural) is wrong. A tasty pretzel shoved inside a M&M, or A tasty pretzel shoved inside M&Ms.

Who proofreads or edits these things? Shouldn't they be smarter than the Average Joe, or are they trying to dumb it down?