Honestly, using it for daily hotel searches for 500 days: The reviews are not worthless.
It requires a lot of sorting out and the results have to be taken with a grain of salt.
I stopped using GMaps and I still don't think they are worthless.
Some companies buy fake reviews, some use shady techniques such as free drink/appetizer for a review. In my experience so far those are exceptions, not standard. I think corelation between quality and GMaps average review score is quite high - at least for restaurants.