I think they both have their place.
Commercial grade black landscape fabric is good at absorbing and radiating heat because it's black, but it has very little mass, it doesn't hold on to the heat. Black landscape fabric is more of a thermal conductor than it is a thermal battery. You need mass to be an effective thermal battery.
It will heat up the soil and the soil does act as a thermal battery too, but the soil can get too hot during the summer. That's why so many people use white pots or light-colored fabric pots because your roots can get too hot, even if you grow in the ground the soil can get too hot.
The beauty of using rocks or water as a passive thermal mass is that it mitigates temperature extremes. During the day when temps inside the greenhouse are excessive, the rocks/water absorb and store the heat which cools the greenhouse, at night that stored heat is released back into the greenhouse, creating thermal equilibrium.
Large commercial greenhouses usually don't use rock because it is expensive and rock doesn't really perform the same function as landscape fabric, i.e. rock doesn't work very well as a weed barrier if cost wasn't an issue they would probably use both.
I build rock walls to create raised beds and use flagstones in the pathways, instead of using gravel, less messy and no rocks in the soil to deal with.
That makes sense. I hadn't considered spilled dirt. Personally I'd look into a construcrion grade fabric with a shiny weed block on top so you could sweep. Some of that stuff tears really easy.
Too funny, you guys are really worried about getting dirt in your..... greenhouse, not making fun of anybody just surprised. Dirt is good, dirt is the engine that drives everything that we love. I say embrace it.
Dirt >plastic
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