I think mods ruin the game.So i would.
That's a very curious stance. Why do you say that?
How about mods such as the Oblivion mod that for example that allows you to see which plants you have harvested for alchemy, with those plants showing normally again after they regenerate? How about the mod that makes containers visually appear to be opened after you check them so you can tell what you went through in a dungeon (or if you're a thief a house), with an option to close them if you so wish? How about the mod that makes the map a color map? How about the mods that improve the UI itself, showing more inventory on the screen at once and improving meters displayed for your status effects? How about the mod that for Khajiit makes night eye toggled rather than a short buff, which actually makes sense lore wise and just avoids having to spam it normally? How about the mod that allows you to put quest items into containers so they don't permanently clog your inventory (and you can disable the mod after putting them in a safe place to avoid accidentally losing quest items).
Oblivion spoilers:
Spoiler There's even a mod that allows you to help rebuild Kvatch itself into a working city!
To add to that there are many dozens of minor tweaks such as horse retextures or bug fixes and such. It's a very curious statement to say you think that mods "ruin" the game. Every mod I listed there does nothing that changes the balance of the game.
I would be extremely disappointed if modding weren't possible. I originally voted that I'd get it for a console instead if it was like that, but in retrospect I wouldn't want to lose the console either, which has at least once allowed me to escape a bugged piece of geometry that trapped me.