Why do they always kill the unarmed - dare I say innocent?

To put it provocatively: are they all such chicken-shits that they only dare to kill unarmed old men and women and children instead of going up against fully armed and trained soldiers of both factions? (exaggeration intended)
If the western world were so invested in getting rid of Islam they'd go shoot armed-to-the-teeth bearded mullahs, not peaceful people praying in church. If the arabic world were so invested in getting rid of Infidels they's fly planes into Norad, not WTC. If white men would feel so oppressed by SJW they'd shoot their very public vociferous proclaimants, not random masses in a public plaza.
I could go on ad nauseam with examples and yet no one here seems to want to ask that underlying question of all these acts of terror - everyone decries the fallout for western civilisation, free speech, white man, yet no one seems to care that it is always the 'innocent bystander who get's shot in the drive-by' because the perpetrators are all just cowards hiding behind a (proclaimed) greater cause - check your premises and the results will take care of themselves.
VSD