What's the point of not keeping it? Some people will only accept legacy payments and they have they right to do so, and people have their right to use legacy at any time.
It would not be any more confusing than having that "Generate Bech32 address" button which already exists there.
And like I said, this could be hidden by default and shown if you enable advanced features on the menu.
In any case, noobs in general don't use full nodes. Anyone using a full node knows what that is anyway.
The idea to use dropdowns came up frequently in discussions on how to support getting segwit addresses in the GUI. We decided to stick with the checkbox approach because we want to encourage users to use segwit. The only reason to have the checkbox is to let people use bech32 addresses when they want to and default to backwards compatible p2sh-segwit addresses. There's little reason to use legacy addresses except out of principle (i.e. those who hate segwit). For such people, they can start Bitcoin Core with
addresstype=legacy, and hopefully those options will be available from the settings menu too (there's an open PR for that).