As a person, rather than a cyclist, I'll offer my suggestions as to why the person may have chosen to lock their bike there - none of which are offered as excuses nor should be taken as me condoning any damage caused:

• The person wanted a soft parking space to protect their front forks since they had to remove their front wheel to lock it up.
• Activity around that bike would be more noticeable and hence the person may feel their bike is safer there (busy bike racks often have bikes stolen from them in broad daylight as people don't really take any notice of what people are doing in them)
• Less chance of damage. I've seen at least three bikes seriously damaged while parked in those racks - from cars either reversing into the bike racks from the parking spaces or by people squeezing through gaps that aren't big enough for their cars
• They mistook it for one of these: