> ... they should devote their energy to try to apply their results to solve real problems.
You might instead have said this about any researcher in abstract mathematics, computer science, and even theoretical physics.
Some people enjoy working directly on "real problems", and that is fine. But plenty of other people enjoy working simply to push the frontier of our knowledge, and that's also fine.
pi-calculus and lambda calculus are both theoretical frameworks, engineered for clarity of notation and thought, in order to reason better about theoretical problems in computation. Neither of them were designed to be practical programming tools, and their merit does not rest on whether they happen to inspire such tools.
One thing that bothers me a little with the pi-calculus, is that unlike some abstract maths or theoretical CS, many researchers sell their results with potential real-life application arguments. After several decades of the same papers studying very similar type systems and equivalence with no application, one can legitimately starts to wonder if this is worth the effort.
You might instead have said this about any researcher in abstract mathematics, computer science, and even theoretical physics.
Some people enjoy working directly on "real problems", and that is fine. But plenty of other people enjoy working simply to push the frontier of our knowledge, and that's also fine.
pi-calculus and lambda calculus are both theoretical frameworks, engineered for clarity of notation and thought, in order to reason better about theoretical problems in computation. Neither of them were designed to be practical programming tools, and their merit does not rest on whether they happen to inspire such tools.