I think a lot of it has to do with availability and cost and common sense. I have a plethora of lemon balm, sage and thyme in my garden, so could feasibly use fresh, but I can't grow rosemary to save my life or know anyone that can. I'm not going to pay $2-$4 for a little bundle from the grocer, so it's easier to obtain dry. Oh, and you usually need more raw material than dry.
There is also the matter of season and spoilage. Where I am, we have at least 4-6 months of snow, so fresh during that time isn't even an option. Doing a bulk infusion with water to last for winter would either take up valuable freezer space or run the risk of bacteria growth, so dry, make it as you need it is the best option.
Long story short, either works, just do what works best for you.