I think the problem is patents without any implementation, or commercial use.
Make a condition of patent defence to actually have brought to market a product that uses the patent. Licensing the technology to someone would also be a valid defence, but it should be within a reasonable timeframe. Patent protection could then be limited to the actual use made of the technology, overly wide patents would be more clearly identifiable, and the patent could be legally reduced in scope without losing all cover.
That would stop patent trolls, but it wouldn't stop big corporation from patenting entirely obvious things and then suing the shit out of your startup.
Make a condition of patent defence to actually have brought to market a product that uses the patent. Licensing the technology to someone would also be a valid defence, but it should be within a reasonable timeframe. Patent protection could then be limited to the actual use made of the technology, overly wide patents would be more clearly identifiable, and the patent could be legally reduced in scope without losing all cover.