The problem isn’t just the current map generator, it is the way it generates things in general. Industry for example is a complete mess. There is absolutely no rhyme or reason to industry whatsoever. I would much rather see a resource for industry set to a specific area then have the need to actually transport it to where it is needed.
Example: a steel mill needs coal and iron (often found in the mountains) a large city would have the mill, while the smaller towns would have the resource which would need to be transported to the city where the mill is. Right now industry is all over the place and most of it is just never used.
Goods for cities is also a mess. I would rather see a system in place where a city needs all manufactured resources to really hit peak growth. Lumber is an obvious early on which would make town with lumber and saw mills important for the growth overall of every town. As the date increases steel would also be required for the larger structures, as well as oil for gasoline for city life.
The changes to cities needing goods also makes the game far more interesting for rail transportation of goods and other resources. The way things are now I really transport most of my industry via road since it makes more money and trips are short, there is almost no need to transport things by rail as the game is now.
Let us use the seeding to generate terrain, but then let is place resources, cities, and industry. Let us build custom maps where we can really enjoy the game, the trains, the trucks, trams, etc.