That is true if we are discussing a single tripwire or booby trap. But the argument avoids the real point of landmines – blanket deployment over very wide areas, making them impassable for military units in the short term, and deadly for the indigenous population in the long term. Nobody rigs up a few thousand pressure plates at a time. Removing landmines from the available military options would mean that this kind of deployment would become impossible – it would mean the end of the mine field.