He spent thirty years lying to and manipulating Scrooge, getting him to see him as an ally and confidante, even wiping his memory to keep it that way.
Then when he noticed he was adventuring with his family, he set up a scheme to get Della to take that launch early. That caused the entire Della mystery, tearing the family apart, putting an entire decade of heavy guilt and self loathing on Scrooges consciousness, and then got his butler and close friend killed to further torment and isolate him just to make sure he doesn’t do the one thing he loves the most.
Bradford was totally fine letting Della stay stranded in space, even shutting down rescue efforts to reach her just to keep Scrooge on his tight little leash.
But when his grandnephews came, he started to feel a sense of joy again for what seems the first time in forever. Instead of living in a dark, desolate mansion alone and miserable, he was happy, getting out there and teaching his nephews and niece the grand ways of adventuring. But with adventuring brought chaos. Mr. McDuck was out there actually living for once, and Bradford couldn’t have it.
So he brings up a contract three decades in the making that forces Scrooge to choose between the two things he loves most: adventure, and his family. His family is an adventurous family however, and Bradford was fully aware they’d keep going even without him, if more reluctant. He was going to force Scrooge to live in misery, having no choice but to sit on the sidelines and watch his family do the one thing that bonds them together: adventure.
I mean, just watching the pilot. Seeing him go from bored and miserable in his office to bright and excited by the end. “Curse me kilts, have I missed trouble”
For the Ducks, adventuring and family go hand in hand. You take one away, and the other ceases to exist. Even with Beakley, his best friend, Scrooge was still miserable because he wasn’t doing the thing that formed their bond in the first place: adventuring.
All this to say: How can Bradford concoct a plan that makes a man go through unimaginable mental torture for a decade, then try and force that same man whose entire sense of self revolves around adventuring resign himself to a dull life of nonadventure by threatening hundreds of peoples lives and still NOT think he’s the villain?