I'll agree the 12.5BTC reward is pretty high but that's spread out across all the users as a "group cost"
The network basically decides that providing the last 10 minutes worth of processing power is worth 12.5BTC and amount decreases every 4 years so the "group cost" will drop while the "individual cost" will rise.
This is why the "fees are high" issue has come up, Bitcoin just reduced the block subsidy to 12.5BTC as opposed to 25BTC, while in the 50BTC era, transactions were often free of any charges.
Even with all of that, an average user will pay less than the credit card fees charged to the shop so most shops would be wise to accept it, even if only to sell it for USD immediately.
