Why is it so hard to find reviews on Turn Key Providers?

[Daniel Ng]

I've been researching turn key providers for a few months now and it seems like every time I find one that has a well put together website or smooth talking sales rep I can never find any reviews from people who have actually worked with them and been satisfied with the experience. Why is this? It feels like it's a super secret club. Even several post on Bigger pockets who mention having experience with various turn key providers they never really mention details or names. Is there an unwritten rule that you have to keep the provider your working with to yourself unless you have a bad experience? 

What do you guys think?