When you have millions of users, and your product has inherent danger, you can't assume the liability for all of them. (hammers and nails anyone?) The only reason that Microsoft has agreed to be liable for their users copyright stuff is because they know this case is a winner for OpenAI and that it does indeed meet merit for fair use. They wouldn't do that to 'be nice,' because not even microsoft can foot the bill for millions of users being sued. Their only alternative would be to not produce the product.