Let's say they made an estimate and aren't sure they can cover the cost. They can evaluate demand by simply crowdfunding that work. It's very straightforward. If there is such demand - they'll get enough backers. If there isn't - they won't, without actually doing anything. Many developers did just that to evaluate demand they weren't sure about. This was proposed to CDPR several times in regards to Linux release. So what stops them from doing it? All these arguments of "not feasible" simply don't hold any ground. Lack of will can be the reason (and I agree with you about some avoiding unfamiliar), lack of resources - not really.
Without knowing the thought process the simple answer is, as you said, the will to do it isn't there. I'm sure they could do it. It's never been about whether it's financially viable or possible. It's about whether they have decided it's worth it. If they don't offer Linux support the answer is clear. I'm not sure there is much ground to be gained by speculation on why they came to this conclusion (as you said yourself). About the best one can do is lobby for Linux support, as you've done here.
i hope they do that so you'll finally have the indisputable proof that the userbase isnt big enough to support the costs.
Eh, the numbers may not tell the entire story (common problem when stats get tossed around). It's difficult to say there is no market for Linux when a number of people are not using Linux for gaming because certain developers do not offer Linux support.
It's basically a positive feedback loop (v.dog mentioned this much earlier with his catch-22 statement)... Something like this...
1. Developer doesn't offer Linux support.
2. Gamer gets game and plays it on Windows because there is no Linux support.
3. Developer assumes there is no market for Linux after looking at the statistics.
I'd be comfortable saying if most games had a Linux version available in a reasonable state at release there would be far more people playing them on Linux.
It's also safe to say a game developer offering Linux support is an investment. Even if it doesn't pan out initially it might do so down the road. Unfortunately, this may not seem like a worthy risk to take for many game developers, as everything they do has a significant risk attached to it.
I highly recommended you maybe search out a cheap windows 7/8/10 retail corp/home key,download the OS images,from Microsoft for free,and use said key. You can very legally buy a retail key for 5 to 18 bucks on most large PC hardware forums. I just bought 3 7's a 8 and a 10 all retail keys,btw,for 45 bucks. Options exist,outside of waiting on a port,that may not come.
Presumably his issue with Windows is philosophical in nature. "Buy Windows this way", is not at all a solution to his problem.