Recently some of my posts in the forum got the 'Off-Topic' tag and got deleted which were normally part of the discussion at first and got about 20-25 replies. But after a day the moderator suddenly deleted the new post along with some other old posts as "Off-Topic" from the forum.  I'm a bit disappointed by this, as 2-4 of the posts here were related to the main thread and active enough for discussion. I got notifications and PM from the forum, but deleted it in anger, so don't know the exact reason. Now I realize that doing this was not right and I realize my mistake. But here I have something to say and that is -
1. Why is a post considered off-topic even if it is correct at first?
 2. And if that is happened how to overcome from there?
 3. Why do moderators take action after someone reports, but not before?
 4. If a post receives an "Off-Topic" tag, how can it be challenged or clarified?
Special Note: I have not made this post for any purpose, it is purely out of my curiosity.