That's one explanation that focuses on the differences between European an American markets.
But also, the Zoe is is in the affordable range for people looking for an electric car in non-massively-subsidized markets (Norway, Denmark), while VWs and Teslas are rather in the luxury range.
The amount of car (utility & status & luxury) I get for Tesla or VW money in e.g. Germany, makes most prospective customers buy either an ICE (looking for a family car), or BMW or Audi SUVs (looking for luxury & status) - unless they are idealists or in search of image polish (business cars bring larger tax benefits for electric cars).
Then there are simply not much electric cars on the market that aren't in the Zoe-class in the first place (although several alternatives are bound to hit the market soon), besides very expensive SUVs and Teslas. And the regular e-Golf pricing is simply not competitive, for what you get.
So most people buying a Zoe is put very simply a "cheapest price will attract the masses"-phenomenon - given what people are looking for (an electric car, maybe as replacement for the smaller second commuter car).