As explained at the time, tanks didn't do much for the A & C, which had 18-19 klb internal fuel already and a larger fuel fraction (internal fuel to clean TOW) than most fighters. The B, however, has a fuel fraction of about 0.3, which is similar to many modern aircraft (Gripen, Typhoon and Rafale for instance).
Engines is right to say that tanks are not to be dropped on a regular basis. However, the option is there, in extremis - for instance, a CAP may be flown with tanks and the tanks dropped if an actual adversary heaves into sight, or strikers may drop weapons and tanks if engaged unexpectedly. It's about the only way to achieve more than 500nm radius, even with a light load, on a supersonic high-g fighter, and the only way to go anywhere with a heavy load.
It's a bit more complicated on a stealth aircraft because tanks are not stealthy. Even if you can drop tanks and be fully stealthy afterwards (meaning that you lose the tank and the pylon, as in the F-22) you have to determine when to dump the tanks based on when you might be detected. That would often be very early in the mission. I don't think that the F-35 has the pylon-dropping option.
0.3 fuel fraction and no external option is not that much, so long over-water ferries are always going to be a bit of a production for the B.
