It also means that tier bonuses shouldn't be too weak. This tier I think was bad not just because last tier's bonus was so strong (that it changed the entire rotation of the class), but this tier's set bonus was completely pathetic. If the bonus weren't as strong as T14 but at least visible, perhaps it would be able to compete more with higher stats. It's pretty bad when people are legitimately using LFR tier items over current tier heroic pieces.
It also means tier bonuses generally can step up over the expansion. The first tier bonus was extremely strong for being an entry-level tier, which, perhaps, should have weaker set bonuses. The final tier bonuses IIRC are typically quite strong, and should be quite strong at that point.