As shortly as I can muster: we live in a world with finite resources. Any consumer of these resources for its own purposes, whatever they may be, is in direct competition with us (all human civilization). Any entity better equipped to gather and make use of these resources will leave us resourceless. The space of human goals is a very tiny and constrained sliver of motivation-space, so by default AI goals fall outside of it.
To quip: The AI does not love you, nor does it hate you, it simply does not care. You are made of atoms that it can use for something else.