it should

Indeed. Originally it was done so that you can exit the satellite remote view in Space Exploration with ESC and keep the editor open. I used it a lot to look up the planet IDs.

I will check how it will interact with the remote view in 2.0, but I will try to come up with something either way.

On closer inspection, the editor still should not close by esc because it can be opened alongside the inventory.

There is a category of windows in Factorio, like the inventory, the machine menu, the blueprint library, that can be closed by ESC, but they cannot be opened alongside each other. The editor does not belong in this category because it must be able to exist while an inventory or a machine interface is opened because you need to move memory cards between various inventories and the editor.

Also, even if I hack somehow that the editor would close by ESC, it is not obvious what should happen when you press ESC while both an inventory and an editor are opened. Should only one of the windows close or both? Which one?

I've added a hotkey that toggles the editor window. It is alt-m by default, but you can change it in the settings.