You're not getting it though. They're not saying they limit it to one claim, they say that under certain circumstances multiple claims during the policy period may be ground for cancellation.
They might cancel it after the second time you "drop it from a bridge", or if you get "robbed" five days a week, and two times a day on weekends.
AppleCare+ only covers damages that you can prove (trade in the old, busted up one for a new, they're gonna be able to make some money out of the parts that can be salvaged), and won't cover phones that you dropped from the boat that you weren't able to get back, so they can afford having a lower price and offer two exchanges at 50 bucks a pop with no questions asked.
An insurance that covers phones that's gone missing is a completely different game, with obvious and inherent higher costs which means that someone that purchases their insurance and never shows anything other than proof of purchase will be scrutinised and might have their policy cancelled.
As I said, if you're looking for an insurance company that doesn't cover its back in this manner - you'll most likely have to look for a very long time. If not, please let me know the name of it