They don’t, HBO is acutely aware of the motivations of pirated content, and even more aware of the challenges they’d face being a stand-alone provider. Not trying to single your comment out but I see this sentiment all the time with HBO. They’ve obviously done the math and concluded that at this point they make the most money by subscription fees to cable providers, DVD and Online sales, then they would - if they started offering every show for sale at the same time as air-date, likely diminishing their cable subscription fees.

It's huge risk mitigation. If they're a stand-alone provider, and one of their shows doesn't draw in the viewership it needs to, they immediately feel that.

But since they've got all this "free" money coming in through deals with various providers, there isn't an as immediate effect.