So far the fishing expeditions in physics have been extraordinarily fruitful, both in the discovery of behavior that had not been predicted as well as in confirmation of theoretical results. But we are still far away from a UFT and there is a lot of knowledge that is still to be discovered in this field. On the total budget that humanity spends annually on far less productive things (such as weaponry) this is a small drop in the bucket. Let's see where it leads and if it turns out to be a dead end then we can all it a day. But as long as every new level of energy seems to give more and novel insight I'd much rather continue one step too far than to call it a day and maybe miss out on something crucial that we just had not thought of yet.

And even no result is a valid result!

What fishing expeditions are you talking about? Every major physics construction project to date has been justified by at least one, maybe more specific expected result that is theoretically predicted. There are a handful of we don't know things going on, like keeping a staff on hand for Voyager probes, but the main project was a smashing success.

former Biologist fisherman, can confirm, a hypothesis helps :)