If you really want your site perform well in search engine without any penalty, then you should focus on the guidelines of Google, which clearly says, “don’t make user fool otherwise it will not good for your website”. the statement is true as we are using review ratings rich snippet to make users or clients fool as it’s unique feature that we can use to increase the CTR or business of your website.
But, we are taking advantages of rich snippet in negative way. Many spam website also using rich snippets even without having any review option on their website.
What I suggest:
Rich snippets are all about specific details on a detailed product, event, person, location, recipe, etc. Typically that information is not found on your home page or on a category landing page but rather on the final detailed destination pages for your products, events, persons, locations, recipes and so on.
Google’s John Mueller said so too. He said in a Hacker News thread:
No, review rich snippets should only be used in cases where “the main topic of the page needs to be about a specific product or service.” — using them on your homepage in general wouldn’t be like that.