Are machines the enemy?

Both in fiction and in the real world, machines are often depicted as a threat for humanity. This position is most often based on two very separate errors: the first being to consider machines — if they attain sentience — would have any kind of motivation or justification to be a nuisance to humanity, and the second being putting the blame on machines when humans use them for idiotic or malevolent purposes.

The first case directly implies that machines (would) apply destruction, war and mayhem as means to dominate humans, or in some stories, conditioning resembling lab rats’. But why? The motive of machines getting anything positive from it seems absurd, unless they should be capable of psychopathy?

Destruction isn’t viable economic policy. If some humans have understood that, I’m willing to bet that sentient machines wouldn’t even consider war with humans.

The second case is a lot broader but it’s mostly limited to the use of machines as tools — or at least means to an end by humans — more than their potential existence as (sentient?) beings. By pushing this kind of reasoning far enough, some (humans) manage to criticise automation, claiming it makes humanity lose something. A rather amusing and eloquent example is Frédéric Bastiat’s Machinery, a part of his collection of essays: That Which is Seen, and That Which is Not Seen.