I never had a good view of what their motivations were. Honestly I've found legal groups in companies to be generally pretty secretive.

But I'm inclined to think to start that groups in a company are incentivized to do what they think their job is... bring something to legal, they'll have a legal type answer. Bring something to the engineers, you'll get some code.

Need a customer to stop clicking a button? Engineering will code it to be disabled at times. Legal will demand a prompt with a legal agreement you have to check before the action takes place. HR might even come up with some training classes ;)