Why would they, the tech didn't exist yet. Your fault for not waiting. I've been wanting to upgrade my phone for over a year now and decided to wait for the 6s. It was definitely well worth the wait.
That is not necessarily true. The A7 on my iPhone 5s was no slouch compared to the A8 in my 6 Plus. I actually felt like my 5s was snappier in a lot of ways.