I am trying to understand why it is required to have a shield for SD.

Are you trying to kill TWF tanks?

Some of us have TWF builds that use SD and tank. (yes besides what others say it is possible to tank while TWF with ac, prr, dodge, and saves)

With this change to SD enhancements multiple builds will be ruined.

If going to keep the shield requirement, answer me this, why isn't the shield on flawless not working as a shield. It does for Unyielding in Epic Destinies for shield bonuses?

Yes I bug reported it.

If going to keep shield requirement then the shield + like on white armor should effect this.

White atm is only one with this property other than shield wands. Make me understand the thoughts behind this please makes no sense to me.