It's not about "spending time and effort." It does not require "time and effort" to see injustice, if you have an understanding of what it looks like and (this is important) the causes of it. It's about coming to grips the world as it treats people who are not like you--and a side effect of that is seeing that the deck is stacked and the dice are loaded and that things are much more grim than they appear to people like--well--you or me.

Instead of looking for wrongs, they become apparent to you, and there's a moral duty to not look away.