When breadboarding the length of the wires on resistors (through-hole) is quite comfortable. The same holds for other components like diodes or capacitors. I presume the terminal length was made to fit this application, because it essentially is similar to how, 60 years ago, valves were wired up with resistors "in the air" (without a pcb).
However, as virtually all through-hole resistors go into a pcb, terminals could be half the length. Or, if they were angled, they could have the correct length for pcb insertion. I have actually seen those, but I can't find them on digikey, for example, so I presume they are not common.
Copper is relatively costly and getting scarcer. The cutting of long terminals only seems to cause additional waste, therefore unnecessary recycling and/or environmental costs.
The question is: is there something holding back a transition to shorter terminals lengths, or would most machinery be able to accept it without problem? Restated: why haven't terminal wires been shortened a long time ago.
I get expect to get answers referring to cultural aspects, as standards reduce costs for everybody, but I am more interested in the underlying technical obstacles (to reducing waste). Would we be able to move on, or not? Why not?