>You can try to rules-lawyer your way around commonly-understood definitions
Despite your assertions to the contrary, "actually free to use for any purpose" is a commonly understood interpretation of "free to use for any purpose" -- see permissive software licenses, where licensors famously don't get to say "But I didn't mean big companies get to use it for free too!"
The onus is on the person using a term like "free" or "open" to clarify the restrictions they actually intend, if any. Putting the onus anywhere else immediately opens the way for misunderstandings, accidental or otherwise.
To make your concert analogy actually fit: A scraper is like a company that sends 1000 robots with tape recorders to your "open to the public" concert. They do only the things an ordinary member of the public do; they can't do anything else. The most "damage" they can do is to keep humans who would enjoy the concert from being able to attend if there aren't enough seats; whatever additional costs they cause (air conditioning, let's say) are the same as the costs that would have been incurred by that many humans.
> To make your concert analogy actually fit: A scraper is like a company that sends 1000 robots with tape recorders to your "open to the public" concert.
The scraper is sending ten million robots to your concert. They're packing out every area of space, they're up on the stage, they're in all the vestibules and toilets even though they don't need to go. They've completely crowded out all the humans, who were the ones who actually need to see the concert.
You'd have been fine with a few robots. It used to be the case that companies would send one robot each, and even though they were videotaping, they were discreet about it and didn't get in the humans way.
Now some imbecile is sending millions of robots, instead of just one with a video camera. All the robots wear the scraper's company uniform at first, so to deal with this problem you tell all robots wearing it to go home. Then they all come back dressed identically to the humans in the queue, as they jump ahead of them, to deliberately disguise who they are because they know you'll kick them out. They're not taking no for an answer, and they're going to use their sheer mass and numbers to block out your concert. Nobody seems to know why they do it, and nobody knows who is sending the robots for sure, because robot owners are all denying it's theirs. But somebody is sending them.