Say what you will about Beppe, but here are facts.
1. He purchased the key players Conte requested in order to build the squad according to his vision. Lukaku, Vidal, and even Darmian (lol, but still). And today's result is the result of that. Makes you think who was really responsible for ignoring gaping holes in Juventus roster selection during his tenure there.
2. His "opportunistic signing" was Eriksen. Compare it to the likes of Ramsey and Rabiot.
Sure, he's not flawless, and not all of his moves were successful. But these are eloquent illustrations to why Marotta is objectively one of the best executives in the modern football. He is, no doubts, the architect of Inter's current resurrection (which is already a given, compared to the club's state before Beppe's arrival).