Actually on average debt is profitable. The reason being is you're taxed on assets you own arising out of debt until you sell, and if you use debt to fund income then your spread-out income is lightly taxed usually.
Where debt is bad is if you have no income arising either from the asset or no income in general.
If anything, you need lots and lots of debt, all spread out, so if any one of the assets goes into negative equity you simply walk away, and the other assets still deliver a return.
Or, in other words, if you get rich enough you can't really lose money.