It's really disturbing that when there's a disagreement between the powerful and the less-powerful, the reaction is so often to defend the powerful, as if they need the help.

Yes. I think this post nails it pretty well in that the author points out that many people would rather see themselves as "people who could potentially screw up and be criticized for it" rather than "people who could potentially end up oppressed and powerless", thus they reserve all their empathy for people who say oppressive things (with supposedly good intent). What to do about it, I don't know, besides (as rymenhild suggested) mandatory sociology classes.