The only thing saving SP from being a boring ride of "you go first > kill this > run away > land > come back later" is the beautiful and varied world: systems have themes, in appeareance, ships, equipment and even music. These things make playing through it MUCH less boring, even exciting at times. But, I think they could have done a lot more with such a huge world. Like making the story work around exploring, instead of occasionally giving you time off to get lost, then find your way back so you could continue the completely linear storyline. Its fun feeling like you're part of something huge in the story, but it feels less enchanting the fifth time you're told to go mess around so you can feel like you're making some impact on the world. I just wanted to fly around on my own and pretend the story was still happening, behind the scenes. If one were to zoom through the story (as you might if you were reviewing the game), you would completely miss the enjoyment of exploring a system for the first time, on your own, with no guidance. The money requirements for continuing the story are very small... it's easy to pass them without doing ANY exploring.
So, what's my point? Although some reviewers probably missed the real enjoyment of this game, cruising through beautiful systems, can you really blame them? The SP campaign is almost a rail shooter. NEVER are you told to go somewhere you may not be able to find by following a waypoint. And that's what kept this game from being the "revolution" it was promised to be: instead of taking a new approach to the story, as a game this big seems to beg for, they built an interactive movie into an open ended universe. This game was probably re-built in many ways, and many times. It looks like they didn't get enough time to build it the way they wanted.