what do you mean by "busy"?
Essentially, I mean that it's easy to add a high
quantity of modded materials without really adding to the
quality of the gaming experience. For example, a lot of people like the big major mods - MMM, OOO, FCOM, Lost Spires, Ruined Tail's Tale, LAME, Ayleid Steps...
Individually, those all do add a lot of good content to the game. But I, and I'm willing to better others as well, often make the mistake of trying to add too much; and when you try to add
that much stuff, not only are you constantly fighting to maintain stability and performance (or spending half your time rebuilding your Bashed Patch, etc.), but by going in 50 different directions at the same time your version of Modblivion loses a lot of its original flavor.
Or, to extend the "vanilla Oblivion" metaphor...I'd take vanilla over vanilla+chocolate+strawberry+mint+coffee+peanut butter+rocky road+butterscotch any day...