Why Nikon does not include BL-5 with MB-D18

[Jay S]

To increase fps of D850, EL18b batteries are necessary together with MB-D18. But to use EL 18b batteries, adaptor BL-5 battery chamber cover is required. This costs $15. But Nikon does not provide this with MB-D18 costing more than US$400 ?!! And this is not easily available. So I have to wait for more than two weeks to get it from USA. This is easy to fix and Nikon should include BL-5 with all MB-D18.