people who pollute and poach are only part of the problem. Speaking for the way things typically are in the US, people elect local representatives (either county commissioners or city council persons). These people make land use decisions and ultimately speak for the people on what the landscape will look like. Unless we have a very educated and active citizenry, these electeds often (in my opinion) make uninformed or selfish decisions which allow development to occur in places that are not suitable for development. Many times the developer gets off cheap and does not have to be responsible for the after effects of development. While candy wrappers, junk and poaching are bad things, massive mud slides from removal of vegetation, sewage spills, impervious surfaces increasing runoff velocity, lack of stream shading due to vegetation removal, fertilizer runoff, etc. are also a critical factor to the degradation of our natural environment.
If something is going to get done, we must all be involved and all demand responsible growth.