As you can read on Trustpilot, 2 reviews with one star were added here in the last few days, which of course made Whale's overall rating worse. When reading through the reviews, however, you can see that these are standard complaints which Whale support responded to immediately.
The Trustpilot is also manipulated by account farmers who post negative reviews to degrade reputation of sites like Whale.io and as of now there are limited reviews of the site on that platform when more people start reviewing Whale.io on Trust pilot then surely their ratings will get better on that platform as well.