On this forum people tend to follow the lead of the tendencies of a few. Start a conversation. Ask a question.
To know why people want to do a specific assignment, or not to do that assignment, you would need a marketing degree, in the least. I agree that, on this forum at least, that it seems you need to specifically ask for feedback. Before I started posting, I read most of this entire forum's previous posts. There is a tendency of a few posters to be able to shut-down posts, or lead a topic in a specific direction, based on their ability to start controversy, where I didn't see controversy, based on 'their experience' and 'their experiences'. Have you signed up with the Facebook mystery shopping pages?
One company wrote what turned out to be a very controversial post about their mystery shopping company's dining assignments and their expectations of shoppers. Even though most dining shops pay in the form of reimbursement plus a $5 fee and expect proper grammar etc., the tone of the post caused many of the 'professional mystery shoppers' to scoff and retort negatively and some positively. The original poster didn't even seem to have to come back and give responses at all and the same posters just droned on about all sorts of reasons they would or would not do that shop causing more traffic to the post and I'm assuming to the company's website. That is one type of marketing campaign.