The dust is horrible indeed, but apart from that the image is what it should be. If you want a darker sky: expose shorter or with lower ISO or close the diaphragm even more. Then you will also record less stars, that is the trade-off. You cannot blame the camera for the light pollution.
If you want more stars: go elsewhere. If you want stars as 'spots', expose some 10 seconds, take multiple exposures (with rather open diaphragm) and use software like deep sky stacker to make it look impressive.