There are plenty of MI’s that are dope and BiS / almost BiS. And if not that, they are certainty good placeholder items until you get BiS legendary for that slot.
I mean one can do dope builds without any legendary item at all: [DW melee] Beginner's Forgotten Blademaster
Like 7 of those items are bought from faction vendors. Talking about easy accessible gear 
Speaking of faction gear and pierce damage, it is a shame that Redeemer of Malmouth has 30% base armor piercing… forcing you to use/find belt/amulet with increase armor piercing and Blessed whetstones together with Nadaan devotion (since you need +233% increased armor piercing to get 100% pierce)
Aren’t you gonna say something about your comparison with a pierce damage weapon to a lightning damage weapon? 