This sounds like a good approach because it removes the possibility for consumer credit. In my opinion, you should only borrow money to make a profit on it.
only monetary profit counts? i shouldn't borrow to buy something that makes my household more efficient, like a dishwasher?
If "efficiency" in and of itself is sufficient to justify making a purchase with debt, you will quickly find all of your financial resources going to paying off debt service. Then you find that instead of your tools serving you, that you are instead spending your time serving your tools.
The way out is to only spend cash (or cash equivalent, i.e. to commit to paying your credit card bill in full each month) on items which cannot generate a measurable financial profit for you.