When we open a *.nsys-rep file, we can see the Stats System View.
If we want to use the profiling results for another usage, we must do copy & paste the results from NSight Systems to spread sheet software(MS Excel, etc). Hence, if the function of CSV export is equiped, we can use this tool more useful. I also think that numerical data will be easier to use if it is output as pure numerical data with the same units.