Why insist? Because it's software! It's easy to iterate, try new things. That's why there's so many new "companies" doing servers. Just take commodity hardware, slap some software on it, and mess around with it until it sounds good
Now, see how many new companies are out there manufacturing CD transports. Not many
The potential is there, and as I said, it's a whole new world that has opened up for high-end audio companies to develop on.
Nothing in streaming audio is less complex than a CD. Guess why? Because of the software involved. A computer, no matter how pared down or simplified, is still a much more complex device (hard and software-wise) than what's inside a CD player. CD player "software" takes very little memory (kilobytes), and can run on 80s processors.
Roon had a great idea with their ROCK, but that's basically a Linux distribution, tweaked and pre-loaded with Roon. And that took care of optimizing one end of the chain, the server (Roon Core). This is similar to what other vendors have done.
What I'd like to see them do is come up with a Roon Endpoint-only version of ROCK, even slimmer, perhaps even eschewing Linux altogether for a bare-bores operating system of their own creating (a Real Time OS would be neat). If you make the OS slim enough, you'll be able to have that run on hardware small enough, and built it INSIDE a DAC, bypassing the need for an external interface altogether.
This is pretty much what MSB had to do with their Renderer, from scratch. Come up with hardware+software small enough to fit into their standard module, and powerful enough to do Roon endpoint chores.
I truly believe we're just in the beginning of this whole new category of products, and as more brands acquire the necessary skillset, more exciting, and fabulous sounding, products will arrive!