I am not a graphics designer but if this product released for Linux i would buy it.
There are 10 types of people those who understand the insides of a computer and those who simply do not.
I use Linux for development because i find it to be more efficient. Why people do not use Linux ? Probably because it is different to what they have learned on and most computers come installed with a operating system that is either Windows or MAC. Most people who buy these sort of computers are the ones who usually watch movies, use the net and write on word. They probably do not know that there is another alternative to MS office. There are alternatives on all operating systems for most applications but there's usually is a learning curve or a UI that is simply not what they are used to and tend to fall back or refuse to use that.
Will it be wise to make Affinity available to Linux?
Yes and i strongly suggest it and here is why.
Windows might have a lot of users but how many of them use photo editing programs and what about mac. Well most people on mac use adobe products so its hard to convince someone to use something other than that. Most people only know about Photoshop to be the best photo editing program out there and will refuse to use something other. You tell them what is affinity they will say meh i prefer to get ripped off and use something that i know how to use and everyone else uses it. Its like the iphone syndrome. I buy it because its apple and there is no reason to switch from what i have learned. No matter if there is a cheaper alternative that has more features.
You release affinity on Linux fist of all the Linux community will explode that there is a new photo editing software for Linux. It probably will be covered on websites like OMG UBUNTU and every Linux you tuber will cover it. Since it will be an upgrade over gimp and there is nothing that will be able to compete with it on Linux it will be instantly adopted by at least a quarter. That is if it does not crash and doesen't have major issues. It can easily surpass the sales on mac. Most Web developers will for sure want to get there hands on it. And believe me most people that use Linux use it as a developing platform.
But wait that will happen with the equivalent blue screens? Or problems that can occur and people needing help to trouble shoot problems?
Linux does not have blue screens and if you do not mess around as a root user you will hardly experience any blue screen equivalent. But in case that there is a problem a solutions is usually found instantly and is posted on various Linux forums. You google your problem its most likely that it is already solved.
As a marketing standpoint Linux can do more good that harm. If it is handled correctly it can sell on Linux more on day 1 than both mac and windows current sales combined. And in the long run it can encourage more people to adopt it on all platforms. More people talk about a product the better it will do (As long as their experience is positive).
Linux Has Free alternatives. They are hard to learn and its usually programs that are made by a group of people working on it on their spare time. Affinity is far from that.
Please do not quote me.