Emails most definitely generate responsed. When we first launched PlusPlus++, lach hall emailed the first hundred or so users that signed up to get their early feedback. A surprising number of them responded back, quickly and with good feedback.
Ben and I spoke awhile back about the pain that bot tokens are tied to users, not teams. Until a better solution comes about from Slack, emails are the next best thing, and I hope we can find some time soon to add that into PlusPlus++.