Inertia and lack of knowledge. Alternatives to Gmail are better in ways that must people don't understand and/or care about. And even if they do, the improvemen

Inertia and lack of knowledge. Alternatives to Gmail are better in ways that must people don't understand and/or care about. And even if they do, the improvement may not be worth the effort. But, they're definitely good enough if people have to make a switch for some reason.