Ten years ago the software wallets were crude, generally for individual projects/networks and not exactly easy to use. MetaMask is so cool comparatively; you can switch between networks, testnets and mains, add your own networks, interact with sites built to use it and it's a browser app. That said I think you're right and this is pretty common in the space as a whole still but it is becoming better. Security is still a huge issue IMO and I would never use metamask as anything more than a means to an end.