Can't comment on Cricket, but I'm researching low-cost carriers at the moment and discovered a similarly curious situation regarding Republic Wireless. I found some strange restrictions in the plan regarding tethering, looked into it and found they don't support iPhones at all. Why? They won't admit to this on their website, but apparently their "cell service" actually uses some proprietary hybrid cell/wifi network, where they piggyback off public hotspots and route your traffic through them when available, so the "cell data" you are paying for is actually priced on the premise that the bulk of it will be utilized as wifi data, instead. They of course can only enforce this in Android devices by futzing with the network stack at a level Apple doesn't allow.
Interesting, I used Republic a few years ago during their beta period. Back then they were very upfront about routing calls/data over wifi whenever possible, even marketing it as a feature on their home page. Now I can't find any mention of routing over wifi on their main pages.
It makes a lot of sense and I have several friends who use similar services. But if Tethering disables wifi (at least connecting to wifi as your phone is now acting as a router) then their hybrid component breaks and only uses cell which may be throttled, limited, or not available. It sounds like more a CYA against higher bills from whoever they are renting service from while keeping their Hybrid setup functional for better service. I'd be frustrated if my budget plan had terrible service when tethering because 80% of my traffic is normally over wifi and works fine but now is being funneled 100% into cellular.
"They won't admit to this on their website"? I think it's more that they won't shut up about it. Their entire business model and their marketing is all based on the idea that most people are around wifi most of the time.
The cell data you pay for is your cell data usage, you (of course) don't pay them for your wifi data usage.
