I don't believe it is disingenuous at all. It could have been lumped in with the other charges, but they are explicity stating this is how much it costs you as the publisher if you wish to use their infrastructure to publish your content digitally.
I think it is disingenuous to assume that $2.58 is some number pulled out of the air to rip the author off. The current meme right now is to assume all digital content delivery is essentially 'free', but this is untrue.
Someone else said AT&T is the whispernet provider. AT&T's smallest data plan is $15 per 250MB (overages are the same rate). The author says they are being charged $2.58 per 18.1MB, which is $35.63 for 250MB.
So Amazon is charging 237% of the ridiculous rate AT&T uses to try to force people to upgrade to a higher plan.
And that's despite the cost that most Kindle users (I'm guessing over 90%) get their books through their computer or WiFi, and don't accrue any cellular charges.
Plus... this is Amazon. I'm pretty sure that given the amount of data Kindles may use they would have been able to get a better deal out of AT&T than your average individual consumer.
And again, this is all on top of the 30% they take that should already cover all of this.
Do yourself a favor and don't investigate the actual cost of things you buy on a regular basis, because you will be absolutely livid when you find out some of the margins being made off of you.
I think it is disingenuous to assume that $2.58 is some number pulled out of the air to rip the author off. The current meme right now is to assume all digital content delivery is essentially 'free', but this is untrue.