One of the huge limitations for text based interfaces is the same as the elephant in the room for people starting programming, especially when they start dealing with others libraries/modules: It's not easily discoverable if you don't know what to look for - there's no intuition. A GUI, at least one that's reasonably well-designed, you can play around in and learn fairly quickly.

Having seen the pain of many users even when trying to dig down through a GUI they're unfamiliar with, I think that while text based interface are often more powerful there's a long way to go before they're more popular.