I agree - but given Google's scale, managing the relationships with these kinds of third party sites could be challenging indeed. Perhaps they could set up a system similar to Webmaster Tool's sitemap submission where you could upload structured data to Maps including links back to your site?

Regarding Sushikartan's revenue, it's not entirely clear but I believe there is no direct revenue from Ted's map sites (he has a lot of similar sites to Sushikartan). He has a few maps sites with partners which probably brings in some revenue, but I think it is a traffic and reputation that is the main goal. Ted already had an exit a few years back, moderately sized but very good for a one-man shop.