Or isn't it more appropriate for administrators to apply any of the options of which includes to either lock the post for a while and delete later,
There is stress of moderation. Moderators even find it difficult to handle reports sent to them because they obviously have their personal life also to deal with. Now imagine instead of moderating once and delete the spam, you save it for later action when there are alot of unhandled report.
or arrange similar shit posts into a separate board and delete later, so as it acts as a reminder to others and to the creator of such post on the kind of post not to make and present?
Arranging similar shit posts in a separate board means to move it to off topic board, it's happening already. Doing this for spammers not to create similar topic is not effective because spammers don't use the search button.