I go back and forth on this one. On one hand, it does not really add anything and for a long time I did not really use it. There isn't much point without an appearance system (or a more crucial one). ...
I like clutter. But not too much clutter. I am a minimalist IRL and clutter makes me kind of anxious. So in sims I like to see that somebody actually lives in the house, but I also like houses to be playable - smooth. I build small houses and I don't use MOO so I don't think I can ever go overboard with clutter. Less is more. I hope it makes sense.
And that's the reason I don't watch speedbuilds anymore. The amount of clutter in those build is ridicoulous.