Google quietly backs away from encrypting new Lollipop devices by default (arstechnica.com)

TL;DR for others

Encryption hurts battery life and performance of tasks. You can still enable encryption on your device, it just isn't default. It's planned to be default for future devices when it doesn't hurt performance as much.

This is also really old news.

Most vendors did not release phones and tablets based on 5 because the performance just sucked.

It's bizarre that they launched the Nexus 6 without someone flagging that up. I'd love to know what internal discussions were had about this.