This would only make sense if the sole effect of not shopping at Amazon was to end warehouse jobs. But the alternative to "shop at Amazon" isn't "set my money on fire." If I don't shop at Amazon, I'll either buy the same things somewhere else, or spend the money on something else, or invest it in something else. When you (and I) shift purchases to Amazon, we're voting to take jobs away from [whoever's involved in getting stuff to us via retail] and create jobs for [whoever's involved in getting stuff to us via the internet].
Part of what I'm responding to here is, your argument seems to boil down to: "it's OK for me to benefit from these people's suffering, because they aren't being physically forced to do it, so I must be doing them a favor." That's letting yourself off far too lightly. Our standards for which businesses we encourage should be higher than "do they have to physically compel their workers to show up" -- unless that really is the best we can ask for.
Part of what I'm responding to here is, your argument seems to boil down to: "it's OK for me to benefit from these people's suffering, because they aren't being physically forced to do it, so I must be doing them a favor." That's letting yourself off far too lightly. Our standards for which businesses we encourage should be higher than "do they have to physically compel their workers to show up" -- unless that really is the best we can ask for.