I don’t really think it was considered foolish as I understand, it’s always been an enticing endeavor with a lot of promise, just difficult to do, much like studying nuclear fusion, most people are really excited by the upsides but dismayed by the challenges to get there, but I think the “a path considered foolish” bit is a bit dishonest here. Which we don’t really need because a scientist toiling away at a difficult problem for decades with a gigantic payoff for the world in the end (a payoff which we will continue to enjoy since mRNA vaccines have a lot more to offer in the pipeline), all for meager pay is a great story itself without the need for such embellishment