I've never even looked at the poem and have beaten Minecraft many times. I'm probably not the target audience though, I generally skip quest text in games.
You should read it. IMO it transforms Minecraft from being just an ordinary game experience into being art, it makes the context of what you've been doing, in playing Minecraft, into something like folklore.
Late at night, having defeated the Ender dragon, having spent months in the game, it turns that moment into an almost spiritual experience.
I was 14 and it brought the silly little block building game where I farmed trees and made dirt houses and turned it into a meaningful story, something that made me think, something that moved me.