That’s a perfectly reasonable question. I would just say look at what DxO’s competitors are doing, as I explained here. Or take a look at Affinity Photo, that still supports an 8 year old OS X release. Admittedly not as comparable as C1 and Exposure in function, but you don’t hear many people complaining about Serif’s macOS support since by the time you run into that you almost surely want new/need hardware anyway. It’s the opposite with DxO: perfectly usable hardware may need upgrading to be able to run a macOS that PL supports, so for me the current/obvious solution is just to use C1 and Exposure instead. All of these applications are perfectly usable, with their own set of strengths and weaknesses. Maybe it only strings me out another year, but I’ll take what I can get and reevaluate in another year.
As it is, DxO looks to be worst in class with macOS support.
Of course, DxO may well have made a well-founded financial decision that it’s not in their best interests to put more effort into improved/competitive macOS support, and that’s their decision. (The way some of their employees “like” posts that are supportive of the status quo and ignore ones that question it gives me that impression, even though I’m well aware that individual employees posting on a forum site don’t speak for the company.) I’m not so sure it’s a winner in the long run since it foments the kind of ill will you see around macOS support. Either make it competitive or drop it. It feels a bit like the PL browser that’s still mediocre after three major releases: there for the marketing bullet, but far from the best.
Of course, this also has to do with Apple’s business model since they’re in the business of selling hardware, but I think the 8-ish years they support most of their hardware with new macOS releases is quite reasonable. Which is not to say I haven’t been screwed by them in the past: I bought a PowerMac Q4 before the switch to Intel that fairly quickly became a doorstop. That taught me not to buy expensive Macs, and as far as I’ve gone since then is the Mac Mini. (Obviously there are those with a real need for more powerful hardware, but I’m not one of them.) Now, with Apple’s disposable approach, in which nothing is replaceable by the user, I’m even less inclined to buy a new Mac. An M1 Mini with 16 GB of ram is probably as far as I will go, but I’ve had two disposable laptops die in the past 18 months, so I’m really not keen on any machine that won’t let me replace the SSD and ram.
Personally, I’m not adverse to the idea of installing Windows on one of my home-built computers and running my imaging software on that instead, but I have a lot invested in Unix-based computers over many years, and switching often just replaces one set of problems with another. (Mac/Windows differences in PL anyone?) Windows Subsystem for Linux has me thinking though, since that may let me continue to use my current backup solution (and more) on a hardware platform that gets more love from the likes of DxO and Capture One.