That makes zero sense. I'm pretty sure that most people wouldn't blindly try out a mixer they found in a post 5+ years old, especially with how there are a couple of very reliable mixers available with a proven track record already.
Also, how do you know it works fine? They might share your information directly with the NSA. Or it might be an NSA honeypot. You can't just assume a mixer works fine just because the mixer spits out coins. I think you are behind the domain that has been registered about 4 days ago.
At any point one of those "reliable mixers available" could turn into a very legit NSA information provider, so if anyone's intentions are about privacy, I'd say Monero is the way to do it.
I remember those Hitman websites on the dark web which were closed many years later after they've received tons of BTC and actually killed nobody. I also remember the trades on silk road (or a similar website, but still on the dark web) cops did to catch drug dealers. You never know who's behind the screen on the other end. You blindly trust? You can get as deep as you think in the crap you've just put yourself into.
But
warning to all users checking out the OP's link, be careful and don't rush to use a questionable service. The link is suspicious because
there already is a service called BITmix.com, OP's is BITImix.. it's easy to confuse these two domains and it's easy to mistype the names too. I don't want to damage the image of any of the two in case one is legit (or maybe even both), but there are many cases of people buying domains similar to popular ones with phishing intentions, because we often mistype links/words so it's easy to access a fake website. Carefully choose the services you're putting your money into.