Since I started playing Elite: Dangerous in early September 2014, I've put over 1200 hours into the game and have never suffered for lack of content. I don't play for what might be, I play for what is. Of course, I've always seen it as a sandbox where player interaction is the real meat of the game, and despite matchmaking/instancing never having been ideal, there has never really been a lack of opportunity for this interaction.
Not that I'm particularly aware of what goes on with regard to the Steam forums, not having been a Steam user since 2004 (I don't like the platform, or Valve's pseudo monopoly on distribution, and I think Steam is probably the most singularly negative thing to ever happen to PC gaming), but if these Steam reviews are honest assessments of the game, there is no need to moderate or censor them, no matter how unfavorable some may be.
SlugwormX answers this quite well, but I'd like to add that once you exhaust the content in all the small-to-medium ships, it gets very tempting to turn to the larger ships in effort to "experience the content in new ways." So, you have to grind to get that small morsel of novelty. This takes an immense amount of time, and it isn't quality time well-spent.
The whole grinder's approach to entertainment is foreign to me; it feels completely counter intuitive.
What could possibly happen once you've achieved your "larger ships" that would fundamentally change what the game is, or make an unenjoyable journey to such a goal worthwhile?
It took me a relatively long time to be able to afford a decked out Fer-de-Lance, but it was never an overriding goal, and I was never not having fun on the way. I can now afford any ship in the game, but I didn't race to this point and I still go back to my Viper quite regularly, because that's an experience I have always enjoyed.