It doesn’t fit with his character

Think of all the previous Money in the Bank winners. While there may be a few outliers (John Cena, for example), more often than not, they fit into one of two categories. Either they’re slimy dickheads waiting for the perfect opportunity to take advantage of a wounded champion (Baron Corbin, Edge, The Miz, Alberto Del Rio, Seth Rollins), or they were plucky underdogs who were making the most out of an opportunity they might never get again (Daniel Bryan, Dean Ambrose, Rob Van Dam). Braun Strowman fits into neither of those categories.
You mean to tell me that Braun Strowman is going to wait until Brock Lesnar just got his ass kicked to come in and pin him? That Braun Strowman, who tipped over an ambulance and a TV production truck, is going to wait for the “right time”? Heck no. Braun Strowman makes it the right time, He does what he wants.
I must say, though, that if Strowman were to win, it would be an interesting twist to the concept. How would Braun Strowman cash in? Would he charge to an empty ring and demand that the champion face him there and then? Does he interrupt the champion when he’s in the ring and cash in right then and there?
If Strowman does end up with the contract, I wouldn’t be overjoyed, but I’d at least be interested in seeing how he goes about cashing in.