All it takes is your company execs or lawyers to be afraid of a stern letter, and ask you to cancel your project. If you're violating their robots.txt, you're probably violating their terms of service that's hidden somewhere. And your company doesn't want to risk having to pay hundreds of thousands to fight a court case. There's also venues besides courts for them to attack you, like contacting the publishers or hosting platforms for your derivative works. It's a chilling effect.
And I'm not making this up. This kind of stuff has happened to me many times.