Exactly. The problem is the same as a casino, though: we now have an "industry", we have thousands of people making their living through these companies; we have a niche that Someone Will Fill if we shut down the big players and create a vacuum. Imagine getting a city to shut down its casinos when it has all the tax income flowing from them... sucking its own blood, cutting off its nose to spite its face, some such analogy. Maybe eating more sugar will cure my cancer.