You're using the pixels for something different than the target audience.
People who want a Studio Display want retina crispness. If you enjoy a 42" 4k, you're more concerned with real estate than image fidelity.
I'm happy with a 65" 4K TV in my living room, but a 4K 27" monitor is borderline too low-res for computer work. Same pixel count, but different use cases.
I think I’m absolutely the target audience: I’m a designer, programmer, animator. Crispness at 4k is still quite good at 1m distance from my face. I’d buy it without hesitation if it came much, much larger.