So shouldn't we be allowed to question how this is possible when some of us have much higher spec hardware and are getting far worse FPS?!?
Let's say it is hard to describe why that is.
You can have the best of the best but if you roam around websites which are like "not for the fainted heart" you can get a lot of mess on your desktop which "might" effect performance, as well as all sorts of "speed up" programs which actually don't speed up anything.
Some of us record their gameplay maybe? Can also be a factor which decreases performance.
I like the music in Planet Coaster, but sometimes I want to listen something else and put on Spotify. Well, I should not do that if I am bothered by performance, because it eats out a large chunk of what Planet Coaster actually needs.
And I don't believe that Frontier isn't doing anything about it. But as most people already said, performance could improve, but it will be in small steps which are hardly noticeable for some of us while others get more than 1 fps improvement after an update.
Yes, you are free to raise the question, there is however no clear answer to that at the moment.