I sometimes use the strobe mode, but only during daylight - typically during less than nice weather. I can't stand strobe mode in the dark. It's too mentally distracting and you can't really see the road or what's on it. I see riders using strobe in darkness and it seems to me that their lights aren't powerful enough to see the road anyway so they display to be seen only.
Anyway, you ain't likely to understand why folks do what they do, and you sure ain't likely to change their behavior. Good luck, though.
-G