Larry, that's simply not true as a blanket statement. It's fine if that's your view, but it is not "poor financial planning" to finance a boat with a tax-deductible loan, any more than it is poor financial planning to carry a mortgage on real estate. They are both tax deductible. Whether the asset appreciates or not is completely irrelevant -- the only relevant question is whether your money does better elsewhere. Your argument might make sense if you are talking about borrowing money beyond one's means to pay, but in that case, the borrower is not "investing" any money elsewhere; they are living paycheck to paycheck which I agree is bad.
It is, however, poor financial planning to use your home (i.e., a home equity loan) as collateral for a toy, and to not insure a six-figure asset.
It is, however, poor financial planning to use your home (i.e., a home equity loan) as collateral for a toy, and to not insure a six-figure asset.