It's not the same thing as just a normal game release, there is new hardware involved.
For comparison the reviews for PS4 hardware and games went live November 13th and the console released on November 15th in the US. The Xbox one stuff had a similar time frame (19th for a 22nd release date).
So in both cases less than three days. I'm not sure why you would expect this to be different. It's still prior to release which is really all that matters.
Not to mention the fact that Sony has been demoing the thing pretty much everywhere in the US for months now as well as at press events world wide and those impressions are well documented.
What are you expecting to hear from reviews that we don't already know?
So you (and others) do have a point about the hardware-I know the ps4 launch reviews were pretty late but I had it preordered on faith in the future ecosystem, not the launch lineup. I've been burned with ps eye, kinect and move, so with psvr I am treating it like a second console; I'll only jump in when the current library is enough to convince me.
As others have said, these types of games are completely new to us and for a minimum barrier of £350 to try the games it's a lot of faith to go on. My main concern with the games is longevity - RIGS looks like it could be in danger of battlefront levels of content, hidden by the fact that it's in VR.
Hats off to those who have faith; you are the pioneers that will cut through the hype over the next couple of months and explain these games to us in more detail.