Okay, let's pretend we're playing a game of tag. Imagine you're standing in the middle of the playground and your friend is trying to tag you, but you don't want to get tagged.
Enfilade means that your friend has a straight shot at tagging you, so you're not safe. It's like standing in the direct path of your friend trying to tag you.
Defilade means you're standing behind something that blocks your friend's view of you. This makes it much harder for your friend to tag you because they can't see you as well. It's like hiding behind a tree or a wall - your friend can't tag you unless they move to a different angle where they can see you.
So, enfilade is bad because it means you're exposed and vulnerable, while defilade is good because it gives you some protection and makes it more difficult for your opponent to get to you.