Yeah, but it’s not a very useful comment. Timing things like pulse width modulation, or other low level HW is what doesn’t work well with a preemptive scheduler in the mix. Audio projects, for an example, are also something that benefits from having proper control. An actual clock is about as far from “timing” things as you could ever really need to get. 1 Hz resolution is generally plenty for a clock.

For PI, there is the C++ bare metal project Circle. All the power of the PI, with much access to the HW, and none of the timing issues.