I thought the same thing on my first foray out into the black. I was 700ly out before I started coming across pristine systems. The trick is to get well off the well beaten track. Main thoroughfares between waypoints are going to be well worn so I suspect what would work well is to head out a 1000+ lys, then veer off in a random direction for at least 1000 lys before straightening out. On my first day trip I ended up with about 30 fresh systems out of about 120 in my cart log, and that was all within a 1300ly of Sol. It's a big galaxy! Lots of fresh stuff to see, you just have to find the hidden corners that haven't already been peered into.