When you are trying to solve a complex optimal payoff problem, you really don't want to get bogged down with lifetimes. That's a completely orthogonal concern to what you are trying to establish. You are not writing production code, you are doing research. It's the core reason why languages with easy REPL and immediate feedback (like matlab, R, python, julia, etc...) are used for research, because you get immediate and interactive feedback. The keyword is interactive.
Once you have to think of types and lifetimes, a lot of the productivity goes down the drain.
99% of the stuff you do in research ends up being consigned to the cutting floor because it doesn't work. The 1% that ends up being useful is the only part worth productionizing.