It's likely because they actually use funds deposited to their site to invest in miners, but don't return significant amounts of earnings to their customers. Just because a cloudmining company claims to own hashrate doesn't mean they're legitimate.
They currently have a 2.6% hashrate, according to
https://www.blockchain.com/pools so in this case i doubt that they're merely a "cloud mining" scam. Still, i find them quite phishy too, mostly because i don't understand their business model.
They let people invest in their hardware and pay them out accordingly, + they pay users for reffering more users, right? That definitely sounds sketchy, and like every cloud mining scam ever created, but, as others have said, they have been in business for a very long time, and they actually mine blocks.
This one might not be an outright scam, but it's still doubtable if you'll ever get ROI with them.
Well i have joined but i m still doubting whether i should but membership or not because this looks like one day you might wake up with nothing in those walllets of theirs