Lol. Dual mining is not always the best way to go. You're pushing your personal opinion like it's a fact — just the same way you're doing it with your "polaris are better cards than gtx 1070". It's not as black and white as you're trying to paint it. Ideally we'd all have our own warehouses with virtually unlimited power and cooling, and then sure — dual mining it is. But in the real world (where most miners live, including the ones that are "worth their salt"), there's always a power limit. For me, there's a couple locations I can put my rigs in "for free", but when I run out of space/power in those — I can only rent apartments and put new rigs there. Renting is the cheapest way to add more rigs in my area, but it's still quite an expense. Cards are a lot hotter and louder in dual mining, consuming significantly more power, and it's just not worth it for me. I can run ~60 cards in dual mining and hit my power limit per location, or I can run ~80-90 cards in ETH only mining, hitting the same power limit in the same location.. the 2nd scenario results in more btc/day. I'd rather invest in extra GPUs and run them in ETH only than dual mine — more profitable in my case, especially at the current crazy high crypto exchange rates.