Spam original definition: Irrelevant or inappropriate messages sent on the Internet to a large number of recipients.
So I'm guessing the Blockland version would be something like:
Irrelevant or inappropriate builds built in the game.
If the host found it inappropriate it could be considered spam to him/her :I
Anyways, I think the host might have been in the right here. Sure he probably acts like a richard, but he does have his own specific expectations when it comes to building.
You can't just drama someone because their server is very strict or different from other ones.
Unfortunately, it happens a lot.