As a service provider I can hopefully answer this in a graceful but honest way. Many providers depend on sales in the BST section for their livelihood and it's a very competitive marketplace. Because the BST section is set up as a forum, you are substantially more likely to have someone visit your thread if it's near the top of the page. So, every time someone posts in the thread that service gets a bump. Additionally, I personally notice sales go up when my other clients confirm transactions or leave reviews. It's reassuring to customers to see that other people are using the service and having success.
I know it's frustrating to wade through loads of posts. But honestly, I would wager that the average BST provider would lose anywhere from 30-40 percent of their sales. As a result, the really quality providers wouldn't even bother with BHW. So it's a trade off. It's that or go to a Warrior Forum model of paying to bump threads. Which is awful. Just my 2 cents.