Despite concerns about the restaurant industry, McDonald's continues to grow its revenue.Considering the current economic environment, investors may appear to have good reason to avoid McDonald's (MCD 0.19%) stock. Even though revenue and comparable sales rose, the company admitted that lower-income customers will probably spend less.Moreover, restaurants like Chipotle and Starbucks have reported falling sales growth as more customers balk at rising prices and what they perceive as less satisfying experienc ...