Steam Spy is dead. They existed at the whim of Steam, and now Steam has changed parameters so that they can no longer work. All of this in the name of privacy, but is it really?
Steam Spy used the default privacy settings on Steam to estimate various numbers around games. Commonly it was used by small developers to see how well similar games to theirs sold. It helped small companies with less money have a better estimate of the market and what was popular. It also sorted games by playtime, popularity at the moment, and so on. Steam Spy was all about transparency, and now some people are worried that without that unbiased data, business practices will change for the worse.
Privacy has been a huge topic recently. Especially with the Facebook scandal in the news. So it's only natural for other businesses to make a push for better privacy practices right? That's all Steam is doing isn't it, just increasing privacy? Well, maybe, but they've left out a lot of other information some people would find more important than whether they own Tsundere Shark dating simulator or not. The information that's still open for all to see by default are profile name, avatar, profile summary, friends list, steam level and badges (so don't win any badges in a game you want to hide), showcases, comments, and group memberships.
If it was all a privacy issue wouldn't at least some of that be automatically changed to private as well? Well, some people seem to think Steam is doing this to try and curb the idea that Steam Direct is drowning the platform in games. It's been common knowledge that a lot of games are doing worse than back in the Steam Greenlight days. However, a lot of that knowledge came from tools like Steam Spy. Without it it'll be harder to tell just how poorly games are doing now with the floodgates opened.
Steam hasn't said why they did it, but they don't really have to political pressure or pressure from publishers. They've set themselves up solidly as the place to sell games on PC, and so it's doubtful any sort of lobbying had an influence on this. In the end maybe it was just something that users wanted and so they put it in place. After all, Steam usually listens to its users so we'll, right?