i don't understand..

Some people here are saying this gold mine can never be economical.

With grades of 14g/t average PLUS silver credits, what am I missing here?

"The Probable Ore Reserves are outlined below:-
? 620,000 ounces (19,000 kilograms) of gold (2,500,000 tonnes at 7.7
grams per tonne gold), and
? 410,000 ounces (13,000 kilograms) of silver (2,500,000 tonnes at 5.1
grams per tonne silver).
The Inferred Mineral Resources are outlined below:-
? 11 million ounces of gold (25 million tonnes at 14 grams per tonne gold)
? 7 million ounces of silver (25 million tonnes at 9 grams per tonne silver)"