A lot of mad people there, but the thing is that a lot of those complaints are only 1 side of the story. They talk about competitors halting pre-orders due to the supply problem and this being the right thing to do. But some of us are happy to put down the cash up front and wait in a queue, at the end of the day if your primary goal is get the hardware as fast as possible then you want to be in a queue and stay in said queue, and cancelling or moving to competitors or whatever is only going to make your wait longer. You don't want to be in a hardware lottery where you have to beat out thousands of other people camping the stores and sniping the stock as it comes in, you will not get your card faster that way. And even then these other stores aren't going to re-list the cards to buy until the current queues are finished.
Where I do agree there's a problem is in the communication, one of single most important things when dealing with people is managing expectations. If you tell someone up front when ordering that there's a huge queue which is moving slowly and realistically you're getting delivery the other side of Xmas. Then people can then make an informed decision to buy or not and if they end up in the queue knowing realistically where they stand, they have no cause for complaining. If they aren't informed before/when ordering then they go into the queue with some random expectation in their mind of when they might get it, maybe that's a few days or few weeks but that's what people do when they don't have the information. They set their own expectations often arbitrarily and eventually those are violated when they learn the truth, and it's that disparity that leads them to be mad.
This is like...people 101...take the same average person, they want product X, product X isn't going to be in their hands for 3 months. Scenario 1 you tell them to pre order with no information. Scenario 2 you set their expectations correctly up front. The same person, the same product, the same wait, but 1 scenario ends in severe rage and the other they're happy as Larry.
You could just have a big obvious warning on the product pages saying the product doesn't expect to ship realistically until 2021 and avoid this mess.