The problems with "Wi-Fi" are numerous. The end result is that generally speaking, Wi-Fi is a hot mess of broken tech that doesn't work.
Oddly, I find Wi-Fi to be the only wireless technology which does work reliably. Bluetooth? It's pure bollocks, it never works. Well, that is, when you're trying to do anything the least bit fiddly. And they permitted all kinds of things which abuse the shit out of the spec to call themselves bluetooth, like PS3 controllers. And my problems with cellular technology are legion. But Wi-Fi tends to just keep on ticking along for me. Routers, those shit themselves, but completely and not just the Wi-Fi.
Actual implementations of Wi-Fi are all over the map in terms of quality, with ridiculous things like: advertising support for an extension that it doesn't actually support; criminally severe bugs in a production implementation; vendors that try to work around bugs that other vendors introduced but in turn create yet more bugs, causing a vicious cycle of workarounds to workarounds; "hide and go seek" with extensions and spec interpretations; ridiculous driver implementations that hold exclusive access over very coarse-grained locks in the OS kernel for long periods of time, causing freezes and/or panics; poorly designed antennas; buggy firmware that never gets updated; etc.
You can have all the same equivalent problems with normal Ethernet, though. Many vendors still sell ordinary 100bTX(etc) chipsets which are total garbage, and people still buy NICs using them and stick them into their machines. I have a whole raft of sketchy tulip clones here because they were $1/ea some years ago at Fry's, back when that was still a really amazing price and not just what you'd expect on eBay. They work OK if you only put one of them in a system, which pretty much crapped on my plans for them, but over the years they've occasionally come in handy. Problem is, PCI is goin' away...
The spectrum WiFi uses is open to be used by literally anything else that complies with a few simple rules, [...] Ever lose your WiFi when you turn on your vacuum cleaner, or microwave? That's what's happening.
Well no. My vacuum and microwave are both brand-name products which seem to have adequate shielding, they do not seem to negatively impact my 2.4 GHz Wi-Fi in the least. In case you're wondering, the vac is a Dyson.
If USB and its "device class" specifications (Mass Storage, Battery charging spec, RNDIS, audio class, etc.) is a ringing success story of how standardization can promote interoperability,
It isn't. Most devices don't use the generic driver, even when it would be better than whatever they actually did.
What sucks about Wi-Fi is that when you have a lot of networks near one another, they crap on one another harder than they are supposed to. It takes extra-special care to make this not happen, and then any dillhole who brings his own battery-powered AP with him can still totally hose your network. But otherwise it mostly works, and often better than the other stuff that's supposed to be better. I had way less radio-related problems when my WISP used Wi-Fi than I do now that they're using some custom CDMA crap. No weather problems either, even though I'm more than five miles from the site. It proves nothing of course, except that the Wi-Fi is more mature technology than whatever they were using.
Now, I have yet to try Chromecast, Miracast etc. but I'm starting to think harder about that, so maybe I will finally learn to hate Wi-Fi. But in general, the only real hardship I've had is with chipsets whose drivers don't support master mode under Linux. This taught me to buy intel and Atheros. Even then you don't get a guarantee, but odds are great and you can always check ahead of time. The thing is, that's good advice anyway, both what to buy and what to do before you buy.