Is it reasonable for hotels to pay salaries like this?

Personally, I don't think there is anything unreasonable. As long as you work hard and obey the law, you won't be deducted at will. Most companies use this method of paying wages in the middle of the month and last month, because a lot of work such as salary accounting and performance appraisal takes time. I am in charge of the personnel department in a five-star hotel, so are we.