It makes a difference in that valuable employees that would prefer to be home for the weekend (to be with their families, for example) are worth the extra money to pay for unrestricted fares. Also, if you were to require employees to stay a Saturday night when traveling as a condition of employment, you'd have to pay for the extended food, lodging, and car rental expenses, not to mention the issue of not being able to retain the best employees. So, for the business customer, it's just a reality that paying for unrestricted tickets is often the least expensive alternative. The airlines' pricing model takes advantage of this fact.