The core consumers are the environmental types, the health nuts, and the obsessive foodies like me. New York's got plenty of all, often combined. I've got two local greenmarkets (i.e. within easy walking distance) and then there's the main one at Union Square in Manhattan - that I visit in its Saturday incarnation when I feel like a trip to foodie heaven. One nice thing is that they don't just supply produce - meat, fish, dairy - all there. On the down side the produce selection is rather limited from late fall through mid spring and none of this stuff is cheap.

Finland has a short growing season and with everyone planting at the same time the crops mature at the same time meaning you'd have to buy your entire years supply of whatever all at once, and store them, or the farmers have to store the produce and dribble them out over the year.  My guess is most people don't have the space to stock a couple of tons of veggies and the farmers cannot afford to purchase the storage equipment and absorb the costs of running 'em.

She believed in nothing; only her skepticism kept her from being an atheist. -- Jean-Paul Sartre

Do Finnish farmers have the right to sell their produce directly? French farmers can sell their stuff on the farm, at roadside stands, or on public markets.

Hence a "farmers' market" doesn't really apply as a term here. Farmers can have market stalls in with the retailers.