I only flew to profitable planets with ADS. Which was sad, really, but I had to "make a living". Otherwise I only flew to several moons promising activity, hoping to find geysers. Those I found like five times before FSS came along.This how I felt about the FSS vs ADS at first too. However, after doing the FSS so many fracking times I've changed my tune. At least with the ADS there was an active part in exploring, we had to fly the ship in order to investigate a system. With the FSS we just sit still and do a zoom & pan blue blob minigame until the system is revealed. I now prefer the active aspect of flying the ship more than the sit and zoom minigame.
What I'm trying to say is that unless a body was profitable, many never flew anywhere before, either. Money and tags (same goes for mapping) and nice pics. No exploration as there was even less to be found than there is now.