Highlight and underlined.Yet the promise you mention can be obtained free of charge. Obtaining it in exchange for money still doesn't make sense from the perspective of consumerism.
This leaves is with the "show of faith" which is arguably destructive when misplaced and in no way concurrent with consumerism either.
You're not wrong. Again, there is 'what makes sense' and there is 'consumerism'. It's important to remember the second one rarely makes sense.
Chia Pets? Furby's? Ty Beanie Babies? Tickle Me Elmo?
Ok, ok, those are physical assets. How about the topic here: promises, right?
Why buy concert tickets in advance instead of at the show? To get good seats, which is a promise.
But gaming doesn't have that issue, you'll say. You're right.
Why buy a game in advance of release? To build hype and secure (hopeful) ability to play day 1 (and fulfill said hype).
Is hype a product? Absolutely! Is it arguably destructive? 100% YES IT IS.
Doesn't change that this is consumerism.
Again, Economics Rule #1: People are Stupid.
So, from the top, you're absolutely right if you talk to me, a similar-minded consumer. It doesn't make sense, it's an empty promise, and I'm throwing money at something that doesn't yet exist. I'm losing no exclusive privileges (that are meaningful to me). So, preorders don't make sense.
If you talk to many others on this forum, preorders make perfect sense. They want the exclusive access (of alpha, and now beta...lol). The 'show of faith' is important to their purchase decisions (charity works very similarly, though nobody likes to discuss that). They want to have the earliest possible access to a product because they buy in to the hype, and the hype is a crucial part of how they enjoy the product...even when they don't actually have the product, yet.
For a really silly analogy: preorders are a bit like buying Christmas Wrapping Paper, Ribbons, and Bows. It's an additional, unecessary expenditure (the opportunity cost of present value by spending earlier than needed) that is justified by the excitement and joy it will illicit prior to reception of the actual product. The truly money-conscience won't use wrapping paper.
Very few are money-conscience. That isn't bad. Christmas would be awfully boring, and I suspect we'd see a heavy knock on the economic boost the holiday gives if we all suddenly were astute with our finances. Frivolous (and early) expenditures serve a purpose, but the language and culture around them can - as you said - be arguably destructive. The implications of the consumer-heavy christmas tradition can find one of its foundations in gift wrapping. So, is gift wrapping bad? Or is it good?
Depends on the consumer.