And your point is?
Of course you can get caught out by having chosen a wrong field.
However if you come to that conclusion at 500ft you are going to be stuffed and best make sure you go into whatever it is, controlled and at minimum speed.
Changing fields this low would end up in tears.
Whereas it is reasonable to expect to be able to retrieve a glider without any damage I think that the stakes are a bit different when you have a FL in an aeroplane. The aim has to be to survive the FL, anything more than that is a bonus.
Experienced glider pilots will choose areas with suitable fields when the going gets less comfortable whereas aeroplane pilots potter along at 1500-2500 ft typically and will get caught out when the engine stops.
By the time they have set the plane up for best glide etc there will be only little time and altitude left to look for a 'perfect field'
FD