I thought it was funny.. (as a photoshop thing not for real because I detest graffiti/tagging...)
I grew up seeing cairns.
Two types : directional ones and at the top of a 'mountain'
(between 7000 and 9000 feet,we had the lowest in the area)
Over about 5000 or so feet we mostly just went up without a path so the cairns helped in finding the right direction particularly in bad weather , not unusual for us to be in the clouds.
At the top it was always a bit of a ritual to straighten and tidy the existing cairns.
Apart from those I wish people did not build them particularly when they could lead you off the path but still I am not militant about that.