Because if you have a 144Hz panel with 10ms response, you’ll notice everything from terrible input lag to possible ghosting and artifacts. Such a monitor simply has clock speeds way too high for its responsiveness. It’s too fast for its own good, resulting in poor performance. You can’t have high framerates with slow response.
In the 60Hz-dominated era, you could get away with 12ms response times (grey to grey). The screen update would still seem reasonably smooth and responsive outside of ultra-twitchy first person shooters. But with 144Hz, even 8ms leads to some chop, which can be very noticeable to many observers.
In essence, the faster your refresh or framerate, the quicker your response must be. Sure, resolution and panel size also figure into the formula, but we don’t want to overcomplicate matters right now.