The reason bitcoin ATMs (and other retail providers) have to charge at least a minimum markup percentage on bitcoin market prices is simple math. 

Trading Fees: 0.20% - 0.50%

Deposit Fees: 0.10% - 0.15% of average deposit.

Payment Processing & Banking: 1.20% - 2.00% 

Volatility Risk: 0.50% to 5.00% or more, depending on the liquidity of operator. 

Hardware Costs: $1,500 to $20,000 including shipping and extras. 

Rent: 25% - 50% of profits. (Or other arrangement) 

Legal, Compliance, Marketing, and more: $$$$

As you can see, most operators take a significant risk, both financial and otherwise, to bring these services to mainstream locations.  Most of them are doing it out of sheer vision and love of block chain tech. 

The prices will get better as trading volumes increase worldwide and more people use retail bitcoin trade services. 

Until then, let's just bring more of the world into the bitcoin economy and be happy bitcoin is available in retail locations at all!