Any developer can bring density to underdeveloped area; that in and of itself is not an overly difficult feat to achieve. We dont need Marlin Spring to do it, because many other developers would have been willing to do it.
As to your point about a developer establishing itself through successful projects and being more inclined to invest in design after completing projects, there in lies a big problem. Why would a developer consistently find the need to bring us horrid quality developments to prove to themselves that they can be successful, before upping the quality of their developments? If anything that's counter-intuitive and illustrates that the developer doesnt believe they can build.
If a developer truly cared about the quality of their builds, they would do it from the start. If they dont do it from the start, that just shows their greed and that they couldnt care about anything else asides from squeezing as much profit as they can by building the cheapest quality build possible.