I see nothing wrong with this. You'd be surprised at some of the stuff startups have to do to get out there and get initial traction, not limited to spam and "faking it till you make it".

The only thing that surprises me is that they were putting up fake reviews so late into the game. The benefits weren't that great at that point, and the risks at least mediocre. It just looks like laziness, if anything. Maybe they wanted to artificially stimulate some growth prior to that new funding round and possibly trying to get acquired, and fake reviews are just one of many methods used at once.