User blog comment:MEEEE123/Why can't we start a new terraria mode???/@comment-25543325-20160125144321

I agree with most of what my predecessors have said, plus, I'd like to add that new modes will probably be allowed once our newest mode will be cleaned.

It's not really about modes in general. They're easy to mantain if it continues to be in possession, if you can control. In case of War Mode this rule doesn't apply - It got out of hand long time ago.