This is rarely a motivator for a small manufacturer to make more money because the infrastructure and tooling costs far outweigh the additional profit of the in house drivers. In house drivers are almost always used to design/build something that is beyond what is available OEM.
I think there’s a difference between unique and excellent. Having drivers no one else has makes them unique and impossible to evaluate the same way we can evaluate small shops with OTS parts. They may also take steps to give the "impression of modernity" (from a Focal marketing slide). For instance, adding a graphite coating, which may do NOTHING to the sound quality. Boom, instant markup, zero value.
Forgive me if I’m too cynical, but of course if I was running a big-brand I’d constantly be looking at ways of cutting costs while at the same time claiming my cost cutting methods were actually purely for the consumer’s benefit. I think both are possible but if I’m not increasing profit margins by vertically integrating I’m failing.
There’s also, of course, the dozens of far east driver makers who actually make decent, bespoke drivers for cheap. Having the time and experience to cultivate those relationships is another way in which big brands increase profit margin.
Regardless of your approach though, if you are a big brand you have to pay for that factory, warehouse, repair, packaging, product development, etc. and that takes money and the only way to get to afford that and actually make a profit is to decrease your cost per driver/increase your profit margin. The other way to say that is to decrease the percentage of cash you have to pay to put those drivers in those cabinets.
Regardless of the motivation, whether purely cost-cutting or purely to deliver drivers with audibly better performance, you can’t get to success if you pay 10% of your retail to driver costs. You have to drive that number down. And that’s fine, that’s business. My message to people who can barely plug a lamp into a wall but want to complain about small businesses using OTS driver because the drivers are "only" 30% of the speaker retail is that they have no idea what they are talking about.