Cconvert2G36: I actually meant it when I said it was a serious question. For example, what risk would there be in a small miner willing to make any size block, several gigabytes or more maybe?
It would become stale as all the other miners don't even bother validating it and build a chain of smaller blocks instead.
To allay the fear, an anti DoS limit could be set just like today, but well above distorting the free market and miners production decisions.