So I was playing fallout 4 and the mods for it are whack. I didn't enjoy it one bit of it. Why do people like mods so much? Just because it's different? The only mods I ever enjoyed (that I know of) was Counter Strike, Dota and PUBG. 

Some mods can be very interesting/exciting, as they can completely change the game plays. For example, here's a Doom mod that tries to make it play like a first-person Castlevania:

But thats more like a new game using a free engine

OK we can talk about Counter-Strike then, which was a mod of Half-Life. Team Fortress was also a mod of Quake.

Not sure what you mean by "whack". Mods in Fallout 4 are incredible, and I've honestly gotten more game-time out of them than just the vanilla experience.

Are they causing your game to crash or what? I don't get the issue.

The mods will hunt you down for this.
Please, do consider tweaking the title.

I was expecting a rant about the moderation on this site.

This thread is a disappointment.

If only they were optional

I disagree

Well, it depends on the mod. I'm more for canon so I don't care for mods that interfere with the mythos of the game and its setting. But personal customization and visual enhancements are some of the things I am in favor of.