Was this a polarizing issue in the sense that extreme approval and disapproval of drone strikes on American citizens is mirrored between Republican and Democrat voters? Or, perhaps voters are more likely to be forgiving when their side is in charge? I'm not commenting on drone strikes. But, in either case I don't see this issue popping up as a frequent answer to why people thought Obama was polarizing.
Relative to his predecessor and successor's activities, focusing on Obama's drone strikes has always felt like a deep cut. Something people bring up when they need to search for a reason not to like someone that reflects on their principles rather than their emotions.