I’m told that Apple feels that these apps threaten the legitimacy of the App Store charts by providing a way for developers to spend their way to a high ranking. Apple did something similar in 2011, when it rejected a number of applications running incentivized app installs within their apps. The company also worries that such apps undermine the integrity of the App Store by cluttering it with alternative storefronts. As one source described it to me, some of these discovery apps create a scenario that’s similar to walking into Nordstrom and seeing a Walmart inside.
Unfortunately, this means that Apple's removal wasn't a misstep and it's unlikely the app will return to iOS with the same functionality. Also, if you use other app discovery applications those may soon get pulled as well.