Given the facts of this SPECIFIC case, it seems arguable that an agency imposing a $700 fee on boat owners to cover the cost of a mandatory on-board inspector IS an "arguable" dispute. One worthy of being heard in a court. It's not even clear who is "right" in this situation. Is charging a fisherman $700 for a ride-along reasonable? If a day's fishing haul is only worth $3000, maybe that's too high. If a day's fishing haul is worth $30,000 and one day of over-fishing can wipe out a fishery? Then the charge would seem perfectly viable. Is this over-stepping on the part of the regulatory agency? THAT'S WHY WE HAVE COURTS.

Note that the issue wasn't even this arcane. The statute was silent as to whether the agency had the authority to impose a fee at all. If the dispute was about how much the agency could charge the owners for their inspectors should be, or whether the fee was "reasonable" or not, there might be some argument that the agency's expertise was relevant. Here, though, the dispute was solely about whether a statute that required boat owners to pay for the agency's inspectors for two enumerated fisheries, but did not have a similar provision for a third enumerated fishery, should be construed to require or prohibit the agency from putting the cost on the owners. That's a pretty run-of-the mill statutory construction case - trying to figure out what Congress' intentions were when they imposed an inspector requirement for all three fisheries, but only put in the fee imposition provisions for two of the three.

I agree that's why we have courts - but under Chevron, the courts would be required to get out of the way and defer to what the agency interpreted the statute to mean. Which in some cases can involve a complicated question of scientific or technical expertise, and in other cases (like the instant one) involves pretty non-technical basic tenets of statutory construction that courts do all the time. In this specific case, there's no reason to think that an agency is more likely to get the answer right than a court would - and given the agency's direct budgetary interest, even some reason to suspect that their construction of the statute might not be simply the application of expertise or technical knowledge.