I think the important thing to consider is what you are taking on debt for - are you using it for investment in something or for an expense? A house or an education is an investment - it can be a good or bad one, of course, but the idea of going into debt to obtain either of those should not be dismissed out of hand. Both can provide a return on those investments greater than the interest cost.

However, if you are taking on debt for an expense (a vacation, a new car when you have a working one already, a new toy), then you are gaining nothing in return for the interest. You could easily wait until you have the money saved up, since those expenses have no extra return for purchasing early.

The worst debt, of course, is when you are taking it on because you simply have more expenses than you do income. This is often the source of credit card debt. If you are growing in debt but not growing in investments, you need to take a hard look at your lifestyle.