Because it is effectively 3 different aircraft now, all with different problems that are eating cash like you read about. 1 variant means only 1 spares line, 1 supply line etc. Though, I'm by no means suggesting it would cancel out the extra unit costs of an overall numbers cut.
It seems kind of knee jerk to me. and it doesn't make the aircraft cheaper for the air force. It deprives them of interservice, and international support. and the program would essentially collapse as the USAF decides it will destroy the program because only it is worthy of receiving them? your hypothesis is "the jsf will cost so much the only option to get more of them is to make them cost more, and then buy more of them"
Jesus wept. That's not what I'm saying at all!!!! Where on earth are you getting the idea that I'm suggesting a higher total is purchased!?
To make this chrystal clear for you. I'm saying it is highly likely the government is going to say overall numbers of all variants need to be cut. Even without defense cuts, the 2400 total wasn't going to happen. Therefore, let's imagine the US government decides that only 1200 can be afforded, leaving the Air Force sub 1000 F-35As. Given the choice of having an all Air Force, all F35A fleet of 1200 aircraft, at the expense of the marines stealth amphib capability ~ or ~ 3 seperate fleets totalling 1200 aircraft that leave the Air Force with far fewer aircraft than it is happy with, then the Air Force is obviously going to have a very strong argument in favour of canning the most expensive variant, which also happens to fill the least necessary role!
in any case, the A is considerably cheaper, so even if I was making the case that canning the B & C would free up more cash for As, the assumption that a greater number of As could be bought is also true, but that's not my argument, ffs.