Give consumers a legal service that's better than the illegal alternative.
It's been a long time since I tried the illegal streaming websites, but when I did, they were awful experiences; low quality streams with heavy buffering, multiple timeouts, full screen pop up ads. Some of them required a captcha before trying each stream, and if it didn't work, tough luck.
Compared to Netflix, where (assuming they have the content) you get a HD stream, no interruptions, minimal ads, at a reasonable price point.