Yes, pixel noise can be annoying. But it can be easily removed with a couple of clicks in Photoshop. Even simply resizing the pattern to 50% (some of the patterns are HUGE, and do you really need Retina resolution in your background texture?) will get rid of most pixel noise. Subtle Patterns are licensed under CC-BY-SA, so you can modify them as you see fit. It would be cool if OP's tool had the option to apply a few simple transformations to the patterns, such as CSS background-size.
