I am in no way defending their behavior, but API calls will always incur some cost - either in backend resource consumption with "paying" customers, or legitimate costs if they're relying on AWS infrastructure.
However, like the whole reddit debacle, API usage isn't always well optimized at the client end, and it can become a negotiation rather than a C&D....unless you're looking to make a competitor as well.
To think, from a business perspective, that any notable portion of their userbase bought the devices with the explicit expectation that it would work with HA would be naive. We're hobbyists, a niche market, the less-than-1% of their market evaluations. Losing those customers while reducing whatever burden or cost they're incurring is probably worth it.
HA doesn't - but while I don't have any Haier equipment to say, the other smart devices in my house which aren't either esphome or tasmota don't connect locally to my devices, but to the vendor cloud API. Ecobee, Wyze, Traeger all do that instead.
Totally agreed. I think AWS API costs are a few cents to the thousand, so a discussion with the developer about the use would be the nice way instead of just kowtowing to the bean counters.