A couple of years ago I was unfortunate enough to be camped a short distance away from somebody with a flashing flagpole and I was trying to get to sleep with my tent being lit up like a Belisha Beacon. In the end I had to get up and ask them if they would kindly turn the lights off. I expected some abuse but they complied without any problems.
Another grumpy old git who does not wish to see flagpoles and flashing lights on an ordinary campsite! Please
They may have their place at festivals and such like, and as a regular attendee to Le Mans 24 Hr motor race camp sites where they are almost compulsory, they are not out of place and in fact add to the carnival atmosphere, but not IMHO suited to regular campsites where they are very likely to be an annoyance to other campers and spoil the dark skies and nature's own light show of a myriad stars.