I've kept some of my coins on Binance for like three years and I haven't lost any. However, I knew what I was getting myself into by doing so, they could've locked my account for any reason and could've ended up losing my assets. I think some of us are addicted to convenience even we know the risk. Those who stick to " not your keys not your coins " rule are usually people who've had a bad experience and have lost a lot of money by trusting a third party.