All it takes is a computer and internet connection to write an "online review". Those review sites do nothing to authenticate the posts.
Very easy for someone who used a .tk domain for spam, porn, etc and got shut down by dot.tk to vent their anger.
Dot.tk wants to protect their "brand" and not get shut out of search engines etc like other free domain providers.
There are "bad" reviews of x10hosting on the Net by people who blatantly violated the TOS (and what they were doing would violate the TOS of 99% of hosts, free or not), had their accounts closed, and then decided to "get revenge" on x10hosting.