I'm half unsurprised as Pixelmator was one of the apps that was extremely-tightly-integrated with Apple's APIs and ecosystem and was an excellent app as a result, and half worried that Apple will make unpopular changes to it as it's a less user-friendly app by necessity. (see also recently: Apple's Dark Sky acquisition and the worse integration of it into the Weather app)
The other half of this equation is Sketch. Pixelmator is great for photos, Sketch is great for vectors and UI design. Both committed to being first-class macOS applications. But Sketch has steadily been losing ground to Figma. I wonder if an acquisition is on the cards there as well?
Figma to me feels geared toward collaborative prototyping specifically. It’s kinda clunky and awkward for creation of graphical assets, which is where I find Sketch a lot nicer.
> Pixelmator was one of the apps that was extremely-tightly-integrated with Apple's APIs and ecosystem
While I can understand that companies want to build cross platform applications, something like Pixelmator shows us what can be done if you take advantage for the platform you're targeting. We're not seeing that often enough anymore.
The few other times I've seen code that truly uses the operating system and APIs it's mostly been server software. It's not unique to macOS either, Windows provide a ton of APIs as well.