Why his apology felt like a non-apology. You could say sorry 100 times and cry your eyes out, but if you don't flat out admit what you did wrong, it just won't come off as a proper apology I think. Yeah it's really hard to come out and say you plaglarise, and list all individuals and journalists you stole work from, but that's what you have to do to attempt starting from ground up again and to try regaining people's trust.
You don't just say, "sorry I've learnt my lesson, i love what i do and i promise the channel will be better than before. anyway here's a new video!"
You say, "Sorry, it's true I plagiarized many of my past work. Sorry to IGN, Boomstick Gaming, Jason, and all other sites I stole work from."