I feel I should precede this with a clarification that I am not part of Salehoo's management, promotion/pr team etc. I am simply a longtime member who is active on the forum.
Every website on the Internet has detractors. That particular one, if you dig into his site deeply enough, is obviously run by Terry Gibbs, and if you keep on clicking through, you'll notice he has or had a personal grudge against Simon Slade, which predates the founding of Salehoo.
It is doubtful that Gibbs has ever actually used Salehoo for anything, and much of his critique comes from the sales page for Salehoo from 2005-06 as well as a few anonymous reviews which have no real information in them. His "review" of Salehoo, which purports to demonstrate why it is a scam, pulls a 404 error rather than a page, so apparently he took it down despite crowing (falsely) about how Salehoo tried to sue him and got trounced in court (Salehoo did try to sue him, but according to the court record they withdrew their legal challenge based on their trademark claim not carrying weight, which presumably means what they cared about was the trademark, not one guy's ranting about an internet service he never tried.)
There hasn't been a comment on his "Salehoo Scam Comments Board" since 2006, presumably because he deactivated it when people started posting positive comments.
Salehoo is exactly what it is. Some people join with expectations that it will be something else. Some of those people ask for a refund, and I assume they receive it. Salehoo costs a fraction of many competing/complementing services such as WorldwideBrands and DropshipDesign, which purport to offer much more but in reality do not. It also less than some specialty print directories that cater to specific businesses, countries etc. So when people grumble about the cost of a Salehoo membership, I can only assume that they didn't shop around much before they bought. Either way though, they have a refund policy, and as far as I'm aware they honour it. Despite a few complaints to the contrary online, Salehoo would not still be using the same payment processor after six years, if they had a continual history of complaints about refunds. They would have been cut off as a liability; ClickBank doesn't screw around with that kind of vendor.
Anyway, short version: I'm sure there are people who sign up for Salehoo, don't like what they see, ask for and receive a prompt and courteous refund, and then post on ten different forums about how Salehoo is a scam run by a bunch of crooks. So my answer to your original question is that yes, I have a thought about SalehooSucks.com, and that thought is that it's crap published by a guy with an axe to grind, who has never even signed up for Salehoo, who might make some valid points about the shortcomings of Salehoo if he had, but he hasn't, so he doesn't.