There are essentially three types of equality discussed in politics. Equality before the law, equality in opportunity, and equality in results (aka income/wealth equality). Equality before the law is liked by most, but few would say affirmative action wasn't just when it was enacted. Equality in opportunity is liked by most, but few people would say it's unjust to allow people to send their kids to private school. The problem I think most people have with gross wealth inequality is that it definitely leads to inequality in opportunity (by most peoples' definitions of opportunity) and some would argue even inequality in law (bankers get their congressmen buddies to bail them out).