> Just because you can propose a hypothesis / prediction that is "falsiable" doesn't make it a worthwhile one to pursue. "Hypotheses" are dime a dozen.
I think there is two things: 1. indeed all falsifiable hypothesis are not worth pursuing (for example, the hypothesis of the existence of a teapot in a 1 km2 area on the surface of Mars is technically falsifiable, you can scan and scan the region for it. But it is a poor usage of time and money) 2. some falsifiable hypothesis are really useful, but when the conclusion is "nope", then it looks like we wasted time and money while in fact we did not (and I think it's what the previous comment is saying).
For the LHC, I think it is very very hard to pretend it was a waste of money. Scanning this energy region was a very good move. It was the obvious next low hanging apple. What else could physicists have done that would have been as informative than that for the same amount of money? Sure, we did not find much (well, we found the Higgs boson, which is a huge discovery in itself), so it is "emotionally" disappointing, and "marketingly" bad luck (the public can think it was useless). But the progress of our understanding of how things work increased a lot thanks to it: before it, we just had no idea what was in this region. We had plenty of hypotheses, with no clue which one was better than the other. Now, we still have a lot of hypothesis, but we crossed-out a huge lot of them.
> The art and wisdom is in choosing what to pursue.
Exactly. On this point, I think the choice made with the LHC is hard to beat. What else could have been done instead that will bring the final word on as much unresolved hypotheses? The question is less clear with the future collider, but if it does not win the best position, it will certainly be in the top ones. So I don't think it is fair to say that people who want to build it are misguided, they still have very good arguments.