There were many/several (to me it seemed like many as I had no idea what a cottage industry it had become) people "trespassed" that were offering private on-site tours. From some of the various forums I read and other people I spoke with, there were all kinds of shenanigans going on. While DAS abuse was one of the most egregious, there were others "doubling up" on fastpasses/lightning lanes by using other people's annual passes (friends/family/"co-guides" would enter and then turn over their magicbands to be used by the "customers"). Back when you got three free to reserve ahead of your trip (and even when you had to start paying for the three) it wouldn't be hard to plan a close to perfect day if you could double that and then work the system as you used each to reserve another. Even with all the cost, there was a pretty penny to be made.
....and now that I type this, it kind of explains Premier Pass. Disney certainly realized they were leaving plenty of money on the table as there was an audience out there willing to shell out to get more access, but maybe not able to get a big enough group together to justify a VIP tour cost.
