Because cloud mining is almost entirely scamm, first they did pay but eventually they didn't pay. they are lost and they are running away with investor money.
i have experienced it
That's true, myself too haven't found any legit cloud mining services. Initially they pay and when days pass we won't be paid. Also we cannot request or do anything as each and every process happens through internet. Now as the price has fallen low no coin seems profitable to mine.
Yes, Bitcoin mining and Cloud mining is waste in investing those because with difficulty in mining Bitcoin it is impossible to make fast Bitcoins in the market. At the same time, cloud mining services will take investment from us and they will share some % to us in the beginning and after they will scam us without any payments.