4.0 Delay and Haste?

Returning player here. I'm reading everywhere that the ideal weapon speed is 4.0 seconds as that allows you to get CAs off without interfering with auto-attack. So my question is are haste items frowned upon now as that lowers your Auto-Attack frequency below 4.0 seconds?

The reason for 4.0 is that even max haste will not mess up auto attack.

4.0 delay are generally desired for scouts mainly because they're the most common, but you wouldn't want to skip out on haste for any reason. The main reason is as the person above said, it's easier for you to get your CAs in without delaying auto attacks. What's more important is that you make sure both your primary and offhand weapon have the same delay so they auto attack at the same time.

So then, for someone without any haste, should they still be going for 4.0 delay?

You get haste from other classes when grouping, so yes.

I've seen some talk of raid Scouts going to 6s delay weapons. They hit harder and with the massive buffed haste in raids, they don't seem to be too slow.
I plan on testing this out once I get some nice DoV 6s weapons.