A little common sense here... Most of FICO's income is paid by lenders. For now anyway, that's who they work for. So of course they're going to tell you to use their credit cards! How long would lenders be using a reporting agency that tells the public to ONLY use credit for major purchase like a car or a mortgage, and only use use it when the interest rate is lower than your investments are returning?
While it's true that the logarithims are set up to reward credit card use, it won't do so to the detriment of the mortgage companies or auto loans. Auto loans and mortgage lenders have their own optimized scoring systems to correct for the credit card marketing hype as well but that can only get them so far.
From a real lender's point of view (meaning a mortgage lender)...
1) Too much revolving credit gives the borrower too much leash to hang himself with. Common sense.
2) Balances, any balances, suggest the inability to pay off that debt. Why would you pay high interest if you had cash to pay it off? Because FICO told you not to?

Common sense.
Your whole credit life should revolve around preparing for your largest investment. Your home. Or use your credit as leverage to create income through investing. Why else would you EVER need credit?
Don't believe the hype. Don't look at credit card companies as legitimate lenders. They are scammers and opportunists who make CRS's a lot of money. Think big. Use common sense!
Listening to the fox who's in charge of the hen house will cost you dearly.