(This is not a formal business case, but preliminary thinking that might be useful for building a business case.)
Intuitively, Semiconductor Printers (probably mostly based on silicon wafers and molecular beam epitaxy, but other approaches can be viable for some purposes) seems like it should "fit" in today's economy. The underlying techniques are old, and proven (and a first generation of patents has expired). We've a variety of systemic issues where this approach seems like it could be fruitful. And, making this work is just hard enough that the prices on these systems is extremely high - ripe for disruptive harvesting.
#1) Entertainment value.
People like to build things. Construction games have historically been steady money makers, and there's a measurable fraction of our population (perhaps 16%?) who just enjoy making things.
#2) STEM Education
There's a lot of schlock information out there, and to distinguish between the meaningful and the trash you need to have some practical experiences. Done right, these printers can teach people some important things about physics and engineering which will later be useful in addressing real needs.
#3) Business Failures
Most businesses fail. People building businesses often need to cut corners for a variety of reasons. Entire lines of semiconductors can suddenly become not available or only available under adverse conditions. In many cases these issues can be solved through negotiation and/or finding other approaches. But having another fallback can help extend negotiation timetables and can sometimes be that "other approach".
#4) Tool building
Currently, there is a lot of red tape and cost involved in designing and building new semiconductor devices (unless you happen to be associated with the right people - who are often in some other country). We can change that.
Semiconductors (and related things: conductors and insulators) include things like sensors and things that make different kinds of light. The underlying fabrication process might also be used for making "nano-scale devices" - perhaps useful for fabrics or medical or biological work.
Finally, note that a major cost and design issue is the vacuum chamber. High vacuum chambers are readily available already, but getting power and materials into them can be a significant challenge. This all changes for space based systems, where vacuum is a "natural resource". This points at a variety of future possibilities and the people who understand how to make these things work well will have some advantages in getting space based computer manufacturing ready for market.