Sometimes we'll have conversation in a venue other than SolarWinds and we want to get that documented in the ticket where they can see it but we don't want to send end users a proactive notification about something they just talked to us about elsewhere.
A private comment is not appropriate since we want it there as a public record of the conversation.
Turning off email notifications to requesters altogether is not an option as we (most of the time) do want emails to go to users when we comment, it's just that we want to disable that occasionally if we're sure the user already knows what we're talking about.
It'd be great if we had a third option - Public but don't notify.
