The problem with these criticism is that they seem to be coming from people who have no idea how Product Hunt works. If you have ever actually had your product featured on PH you would know better than this. Here's how Product Hunt works:
1. There are many of those so called "Insider" users.
2. Then there is a 2nd tier group of users who can comment.
3. Then there's the rest.
The tier 1 group is not as small as you think, and they are pretty diverse group of people from all around the world. When they post something, it goes up straight to the featured page. There is no censoring. They are definitely not paid by producthunt the company to submit these new products, they're merely users sharing what they discover. Their main incentive for posting on product hunt is to be the "first one" to discover a cool new app and share it with others. Now if you understood this, think about how ridiculous all your speculations are.