That would be an argument to start even sooner rather than later or never. If you want to combat the usefulness of the research the only arguments you can make are that the results are not useful at all, or that they can be obtained cheaper, faster, or more reliably with other means.
The "it takes decades to bear fruit" works even against education. And I'm sure nobody would agree to be barred access to any tech that was the result of decades of research or simply took decades to reach market.
I'm also not a fan of this project simply because I don't think an incremental advance in colliders will bring anything new at all, certainly not because it will take too long to reach market. As the saying goes, you can't cross a chasm in two small jumps. To achieve the next breakthrough we need something on a scale we're simply not capable of building now, or soon.