The customer at a cheap hotel is likely price sensitive, and is unlikely to pay for wifi. They'll either use their phone data, or just go without. So the hotel

The customer at a cheap hotel is likely price sensitive, and is unlikely to pay for wifi. They'll either use their phone data, or just go without. So the hotel might as well just provide free wifi to compete with other cheap hotels. For high end hotels, the customer is much less price sensitive, and is more likely to pay for the wifi without thinking about it. Many customers at high end hotels are also business travelers, who don't care about price because they aren't paying for it.