Remember, very few Marriott's are corporate owned. Staff at non-owned properties, including those who send information to MR, are trained by Marriott but managed and employed locally. They often can reflect the corporate culture of the owners/managers rather than that of Marriott, unfortunately.
IME, about 8% of our stays require some sort of follow up. Most are at select service properties, and all follow-ups have been at such.
Pat