This drives down interest rates, and as they decline fewer and fewer people invest in lending institutions. This is textbook stuff. But we're not close to a textbook environment. For one thing the interest rates are not set by the market, essentially they are set by the Fed. The Fed is all for low interest rates to make lots of money available. Investment in lending institutions, or lack thereof, has almost zero to do with the money supply in todays world.
The Fed sets rates for certain regulated transactions (deposits and withdrawals, bond sales). That's not all the transactions that exist. Consequently a very large business operation like Wal-Mart can hold the line on inflation through astute bargaining (buy mass quantities low, sell retail cheap) and at the same time plough profits back into capital expansion and NEVER NEED TO BORROW MONEY!
The effective interest rate for a Wal-Mart can be 0% if they wish.
Then there's the credit card ~ make your own money!