Why is charge cycle count not allowed under iOS API?

First, can someone confirm, as the developer of System Status (techet.net) states, regarding the charge cycle count, "This information unfortunately is not accessible through the iOS API. In the past some apps managed to use private API (which is explicitly prohibited by Apple) and sneak through the review process."

Is that correct? If so, can anyone shed light onto why that would be? Apple frequently refers to the cycle count in its own battery discussions, and yet no longer seems to make that info available in iOS Settings, and I can no longer find it in any apps in the App Store. Curious.

Without that statistic, would you recommend that I just use something like "Design Capacity" as reported for example by Battery Life Doctor (Wei Zhe), indicating, in my case, 1400/1810 mAh (77%)? I'm inclined to think that at that level, it might suit me to replace the battery, eh?

Thanks.