I think an increase in Mcdonalds pricing is a small price to pay to ensure the people making your food is earning a fair amount.
You personally may well think that. Undoubtedly there are others that also think that. But McDonalds is a huge corporation with, I'm sure, a very large and experienced market research team who have thought very carefully about where to price the food. It will be at the point where there is the maximum cost they can get away with, without driving away so many customers that they begin to lose money. Companies as large and as long-term as McDonalds are usually VERY good at identifying that point. And the logical inference of the price being set at this point is that whilst you might be happy to pay more, McDonalds have calculated that more people aren't. Otherwise the price would already be higher just for the sake of profits.