Definitely open to changing this, but our thinking was that if someone would want to be a troll and leave an unjustified 1 star review on a new product, or any other product that does not currently has any ratings, and their 1 star rating would show up right away, it is going to make it look as if something might actually be wrong with that product and discourage others from acquiring it.
This is particularly bad for any free assets where it would not cost the troll anything to acquire it, and leave that review.
I am not sure if a reporting feature would help with this without accompanying text reviews, as without context it is hard to report someone who left a one star review?
Again open to changing this, for example maybe paid for assets show reviews right away and free ones need at least 5 ratings, but just stating that this is one of these things that I think will always leads to some pros and some cons no matter which approach we take.