Nah, not really. I guess it depends on what the Developer set out to do, and what the modders set out to do, since they tend to have opposing viewpoints on what is GOOD in a game.
Odds are, if the game has a massive modding community, it usually means that a large portion of the playerbase likes the overall game experience, but disliked the developer's vision. A good game needs a good vision, and if you don't like the vision, then maybe you'd think the fanfic-tier stuff was good, but honestly, I have yet to come across a mod for a game that was better than the original, vanilla product.
Vanilla games are coherent, finished visions.
Mods are always critiques of finished visions, and often lack cohesiveness with the rest of the original game, which is important if we are to judge a game from an artistic point of view.
But hell, if you don't really care about graphics or immersion, go ahead and mod your game to hell. You might learn a thing or two about game design and/or programming while you're at it. But you'll never accomplish the developer's vision better than he/she did.