Everyone once in a while I see users (mostly new ones, no offense to them) comment asking for clarification on answers or questions from users that are no longer active on Superuser. They haven't "been seen" - according to their profile - for years.

While answering and expanding on old questions is awesome, and I encourage it while helping new users in reviews, it would be helpful for users to see that their comment directed towards a particular user might be in vain.

Of course, another user could come along and help them out, but if one specifically asks a particular user something, it may be a waste of breath if they are otherwise gone.

Related:

I've also noticed on certain questions that the username is greyed out - I'm assuming this means the profile is deleted. Does this happen after a certain amount of inactivity, or do accounts exist for all eternity unless deleted?

Every once in a while I see users (mostly new ones, no offense to them) comment asking for clarification on answers or questions from users that are no longer active on Super User. They haven't "been seen" — according to their profile — for years.

While answering and expanding on old questions is awesome, and I encourage it while helping new users in reviews, it would be helpful for users to see that their comment directed towards a particular user might be in vain.

Of course, another user could come along and help them out, but if one specifically asks a particular user something, it may be a waste of breath if they are otherwise gone.

Related:

I've also noticed on certain questions that the username is greyed out - I'm assuming this means the profile is deleted. Does this happen after a certain amount of inactivity, or do accounts exist for all eternity unless deleted?