Your intuition is good, I think it's the terminology/semantics that are causing you confusion. What you're describing is a valid way to make money as a trader, but most people don't call it market making. The wider you quote relative to other market participants, the more risk you take on - because your volume is lower, you have to hold on to your positions longer, exposing you to greater fluctuations in price. Market making is very much about not exposing yourself to this kind of risk.

In real terms, if you quote a penny wide market, there's a much greater change that you can both buy and sell in a short period of time to capture that penny. However, if you quote a 10c wide market (when everyone else is quoting a penny), you might buy shares at $10, but it might be a much longer time before anyone wants to buy them back from you at $10.10 - in fact it might be never, they could go straight to 0!

Again, quoting that 10c spread is perfectly valid, it just means that your edge begins to be less about capturing "flow" as much as it is about predicting the direction of the stock over a longer time horizon.