While it's certainly a good general policy to not abandon significant segments of your user base, this is not a conflict of user ignorance vs developer laziness. The real question is whether preserving IE6-8 functionality is actually a good way to serve your customers. The resources you dedicate to retaining that 10% might be better used to improve your service for the other 90%. Focusing on modern browsers will also help to attract new customers who won't lock you deeper into these technical shackles. While this doesn't have to mean directly antagonizing people, it may involve making the site unusable and 'ruining' the experience for some.