Huobi, the same exchange which uses clients funds to invest in high risk products for their own profit, passing all of the risk and none of the profit on to their customers? Huobi, the same exchange which were found to be running a fractional reserve system? Huobi, the same exchange which did all this without telling their users and then lied about it?

They want you to store your funds with them for the exact same reason a bank does - so they can invest and lend your funds out to make themselves profit. The difference here being that your funds aren't insured like they would be in a fiat bank. If Huobi make a bad investment decision, or a borrower doesn't pay up, then say goodbye to your coins.