It is sad that they do this. they use us to bank roll their system
why is that sad? they make a product you want ....
Almost every successful product based business grows this way. If people did not buy Bitmain miners they would not have the money to innovate and bring out newer, faster, more efficient miners. And you can replace the word miners with widgets and Bitmain with any company building cutting edge products. Tesla has done the exact same thing as have 100's of brands we buy and use every day.
Bitmain has a lot of faults, like there deplorable repair system. But it's a well run business in most respects.