The faults you mention are precisely why companies like 8Dio and Spitfire don't give me or content creators like me NFRs... They bank on pre-release marketing rather than practical reference and criticism. It's a general rule to rely on marketing and curated quotes rather than uncontrolled opinion and example when it comes to being a "company" that has "consumers" rather than a developer that has tools.
I'm not very vocal about this particular subject (right now... but I have a video planned) but I am 100% dead against pre-orders for sample libraries and I don't tolerate it in the slightest. It's where "customers" become "consumers" to the devs and/or marketing team and it's straight up capitalism and I'm not afraid to say it. Which makes me all the more grateful for respectable devs who put out composer tools with no strings or hype attached.
I think you're correct, this is beyond passion projects - these are large businesses embracing consumerism and the dream of being a creative as a job. We do need devs like Spitfire, OT, Heavyocity, 8DIO, etc because they are the ones really pushing the envelope. There aren't a line of Alex Wallbank type people that can take on huge companies by hitting above their weight.
Spitfire at least has people like Christen Henson (and others) driving their own community with interesting content and ideas beyond merely selling products. The interviews they've done have been excellent, and I've learned a lot from people they have interviewed. While it definitely helps sales (it's absolutely marketing to their products and credibility), I think part of that is genuine - and it does provide value to the community. Yes, there are independent companies that push things forward, and often provide better value, but rarely better overall quality on a whole, and if it is better, it's usually doing a small number of things better. These big name libraries like BBC, HZ, JXL, etc are a symptom of the project based nature of coming up with cues on a time-line. If you're making money, and a library is rough around the edges in places - do you really care that much if that library helped you solve a problem?
The tougher part is the hobbyist or new person trying to break into the industry who is getting pushed out to some degree by larger developers budgets blowing up, and being forced to take risks on what to buy when the stakes are high. That's where your reviews are super helpful. I think pre-orders are more a symptom of the market than the developers themselves. The fact that people line up to pre-order tells you what you need to know. They feel the products fall into a certain range of quality that the consumer is willing to forgo the risk for a discount. I think the discount is the key, because without an incentive, who is really doing a pre-order? It's not like they are running out of product.
There was a funny thread within Spitfire BBC talking about a sample tail mistake where you could hearing singing. For the amount of recording time Paul Thompson quoted (which I believe), it would be a full time job for roughly four people just to review and trim samples for quality control for 6 months+. They needed pre-orders for overhead, because to do what they are doing, you have to feed the beast. To work with HZ? To put out so many walkthroughs and new products. To have OT work with JXL? This trend will only get worse as the content gets more expensive and elaborate to the point the "consumer" expects more and more with each release. It will be a good topic to discuss, because I think it's going to intensify in the industry rather than just be a handful of huge companies using such aggressive sales tactics.