To provide a custom GUI, you would need people to click on a link in the email, which sends them to an external website. Or, you would need to have them use an

To provide a custom GUI, you would need people to click on a link in the email, which sends them to an external website. Or, you would need to have them use an app, and make sure it is installed. In both cases, the users would need to understand the UI. Even the most super-obvious UI takes a little focus to follow and use properly. Especially if they want something a little out of the ordinary ("if X is good, then X, otherwise Y, but only if Z"). Compared to those, writing a sentence in English actually sounds fairly convenient - that's how humans communicate naturally.