Looks like the mods are being nice, merging the post when they could've just deleted it since it broke the forum rules.
Technically they deleted your second, third etc posts, then edited your first post and add the content from your deleted posts. Except you post the same thing, the moderator will delete it without merge your post.
A merge post IMO is worse than a deleted post because it means you made more than one post that can easily be one post.
I don't think so, a merged post mean your post quality still qualify the forum's standard, while deleted post mean your post is bad.