Because ELO and leagues are concepts that don't quite match?

The idea of ELO: a 200 difference between 2 people should predict that 75% of the games are won by the better one. This works really good.

By moving leagues up and down, depending on how many players are currently playing kdice really taints the ELO correctness.

*still trying to see how simply relabeling three tables stops them from filling*

Things change in kdice. They change for everyone, at the same time, in a predictable manner. There is no unfairness.

improving elo rank should not be determined by playing at the "right" time, even when its predictable, when you can get most of it.

It looks like 1700 will replace 1600 soon.
but it is a little counter-intuitive the way the tables come and go due to this 250/1000 restrictions.