Extremely. Need to set up a mail server and some sort of daemon service to reply - and reply with what? The output of lynx -dump on the HTML pages that make up the site?

Not to mention it's implausible that email would save either time or bandwidth, considering how barebones the site is. If such people exist, they are best off being told they are idiots, to prove their cases about email being more efficient, or working on the codebase to reduce use of JavaScript (which is the principal tech that breaks textual browsers).