Iterative loops are much easier to analyze and reason about,
This is not the case. Loops and recursion can be translated into each other, hence are of equal complexity in terms of reasoning. And you see that when you write down the Hoare-logic axioms for either.
What Dijkstra had in mind was probably simple, syntactically constrained forms of loops, like for-loops where the loop variable is read-only in the loop body. They are simpler than general recursion, sure. But there are corresponding simpler forms of recursion, e.g. primitive recursion or tail recursion that are much simpler than general recursion.
What Dijkstra had in mind was probably simple, syntactically constrained forms of loops, like for-loops where the loop variable is read-only in the loop body. They are simpler than general recursion, sure. But there are corresponding simpler forms of recursion, e.g. primitive recursion or tail recursion that are much simpler than general recursion.