In light of the response, you could even say that mahalo employees might prefer to resign via email rather than to face the full brunt of the response in person, your assumption could easily be right and there might be a good reason for it.
In which case you have an opportunity to wake up the next day, decidedly the bigger person, wholly assured in your decision to leave, and with no regrets about how you did so.
opting to email rather than hand in a resignation is not going to undermine anyone's decision to leave.