[hutzlibu]

"and it's just as likely that their diminishing was due to there being less costly ways to kill people."

Politicaly costly, as more and more people pressured for more human ways of war. Because mines are a very effective and cheap military strategy. (where mines are you don't need so much troops). I say it was the boulevard pictures of children without legs, that did it. And maybe will so again after the first killbots gone rouge..

Because I doubt any big military would miss out the opportunity to at least be able to flip the switch to let them operate and shoot autonom, when you have more cheap massproduced robots than operators and need them and or the enemy is jamming you and the situation is critical.