Looking around Scooploop I have seen the effect that members leaving has. If you decide to 'leave' Scooploop, then unless you have a reason to delete your posts/comments, then there is no reason to do anything. There are more than 10,000 members on Scooploop, if you look at their profiles you will see many with no activity at all. These accounts are doing no harm; the member may be a reader or no longer be around.
If you just want to not be involved in Scooploop for a while for some reason, you could turn off PMs, so as not to waste people's time, and put some information in your profile. You can then 'return' at any time.
Deleting your account leaves a post with deleted comments, and ruins the post for readers, current and future. Look back on some old posts to see for yourself.
Also, if you are a big contributor in a loop, deleting your account deprives members of any interesting/useful information you have posted. If I were to delete my account, then the IT loop would be almost empty.