This Metro is fine, if you're looking for the best supermarket there is this isn't it, but if it's convenient I'd go ahead and shop here, there is nothing wrong with the food.
I believe the biggest reason this grocery store is getting bad ratings is the lines and the crowded isles, which I agree with. It is almost impossible to shop here without getting jostled by a customer or two and if I am already cranky, I will probably leave this store pretty agitated.
The positives about this place are a decent selection of food and fresh tasty produce. It is also quite large considering it is right inside the Yonge and Eglinton Center. It's also clean and they have free (well validated) parking underground.
I shop at the Metro at Bayview and Eglinton more often just because it's bigger and less crowded but this one is so convenient and I don't have any strong reason to stay away.
So my advice is to put this rating into perspective and ask yourself is a busy store with long lines worth staying away from if it's convenient? For me, the answer is no.