It doesn't matter at all in the first place though. You could have one weapon with lfie steal, and use bloodthirst. Or 2 weapons with it.
It's true WH is a EHP loss. But a huge source of DPS. you can make up the EHP else where.
If you're 2h, then I can understand the WH. As DW IK belt is the best all around belt. You can use WH as DW but that basically requires that you have monster dps + bloodthirst passive, and even then RD packs will still randomly eat your lunch on high MP.
Add in the fact that the belt is one of the easiest pieces to use for 2/3pc (2pc lets you drop one slot of AR so running it can be a dps increase) and IK belt is a no brainer. Yes, WH is more dps but giving up a slot of LS, a boatload of AR, and making it harder to get 2pc IK just isn't worth it most of the time.
Obviously this doesn't really apply to 2h, because 5-6% LS Skorn is the way to go anyways, and that + bloodthirst is more than enough for even MP10 RD packs.
Really, running IK belt + IK chest is the one of the most efficient setups as you get 210-220 AR, 3% LS, and a ton of str/vit in just two slots. You can run IK chest + gloves/boots/helm but honestly those are all worse than their alternatives in both dps and EHP (gloves can't roll AR and trifecta, helm only rolls AR randomly unlike mempo, and boots won't have as much str or HP as a decent pair of ice climbers). The IK belt is only behind a solid WH in dps, and is unbeatable in terms of EHP when paired with an IK chest (which is the best chest hands down).