Because the game is rigged to have us play as heroes rather than outlaws. You can go on a hour-long killing spree, terrorise the poor folk of your chosen town, and slaughter any law who might come to investigate, but if you make the mistake of feeding your horse an apple on the way out then the game decides you must be one of the good ones and gives you a pass. It is ridiculously hard to maintain negative honour. I play as an honourable character, have the natty suit and everything, but I like the idea of through and through bad eggs wandering around, so it would be great if negative deeds weren't quite so easy to erase from the slate. Literally brushing your horse offsets murder. It's crazy.