Although as a rhetorical question, what would you consider "inferior quality"?
Palladium books? (I kid.) (Kinda.)
No need to ask it as a rhetorical question, I'll answer.
While the CMs that we did get were definitely premium quality, there was a lot in there that could be cut, and still have a very solid product without being "inferior".
Any time this conversation comes up, people tend to conflate the two very different elements of what it takes to get a book done: production costs, and printing costs.
The former consists of the many, varied creative efforts and costs that go into a book: writing, art, editing,
layout, fact-checking, proofing, and development work. These costs are a major piece of the overall cost to produce a book, not a minor consideration. The reason I underlined layout is that it's consistently the most-overlooked element of that process. It's often a significant cost of production, but it's one that customers almost always totally ignore. And layout may be the most important factor in whether a book "feels" modern and high-quality, much moreso than the paper it's printed on.
The latter, printing costs, is self-explanatory--it's all the elements of a physical product: paper stock, B&W or full-color, cover stock, hard or softcover, and how many of that book you're printing. Remember, smaller orders are generally more expensive to print, not less.
You can certainly tinker with printing costs to adjust what you need to pay up front to print a book. Go all the way up, and the next Combat Manual could be leather-bound and smell of rich mahogany, if you can afford the printing costs and think your customers will buy that. Cut too far, however, and you're releasing a product that doesn't meet current marketplace standards. Gotta find the happy medium, at a palatable cover price to customers.
But to answer your question, to me, cutting corners in
production costs is when you start getting into "inferior quality." Now you're not paying a competitive enough rate to get good writers, skimping on art, rushing the edit job, and not giving layout the time they desperately need to do some cool stuff. All just to shove a book out the airlock for the sake of being able to say, "it's out."
Sure, the grogs and the die-hards may not care because they just want new content, but that's no way to entice the new players that BattleTech absolutely needs. You may be okay with cutting the full-color pages and four-page mini spread. But those things may also be exactly what hooks a new player. What you consider a "solid product" may be far behind what a gamer in the modern marketplace expects. Hopefully, a company has done some market research to have a good understanding of what current customer expectations are.
Important: remember that releasing something as PDF-only or POD does not and
should not save you much on production costs. Yes, you're saving the printing, shipping, and warehousing costs, which does bring certain products back into the realm of feasibility. But every product should be held to the same creative standard, regardless of distribution method. That's the ideal, anyway.