Your OP was clickbaity and sensationalized.
It's ok to want Mullvad to move away from gmail for ideological reasons but that was not your tone.
You claimed that because of that "they don't give a shit about user privacy". You thus implied it affected user privacy when that's clearly not true.
Yes a user can doxx all his PII in a customer support email and then reuse the same mullvad account, but at that point, that's more of an L to him than to mullvad. Personal responsibility is irreplaceable.