My guess is the extra 10 is to help Sprint build their 4G infrastructure. Pretty much the same reason the bump was there for the 2G iPhone to the 3G iPhone. They needed to build up their infrastructure to support more devices and need the money to do that. They can't build the towers to cover the users without the money. I don't blame either company for that.
Also, At&t AND Sprint didn't call the extra $10 fees for either of their plans for "3G" or for "4G" respectively because neither wanted to refund people who were out of coverage areas.
As for bleeding dry...
Cheapest AT&T iPhone 3Gs plan with unlimited messaging:
$39.99/Month 450 Min + Unlimited At&t to At&t
$30/Month iPhone 3G Data
$20/Month Unlimited Messaging
Total: $89.99/Month
Cheapest EVO 4G data plan on Sprint:
$69.99/Month Everything Data Plan 450Min + Unlimited Any Mobile to Any Mobile
$10/Month EVO Data
Total: $79.99
Coming from an iPhone I don't see how this is an issue... Even with the extra $10 it's still cheaper. Now, if you don't get the unlimited messaging, which to me I don't care, it ends up being up to a $10 swing the other way. For me I also get a larger corporate discount with Sprint than At&t so I still come out ahead.
Nobody is ripping anyone off here. You're getting what you pay for.
Well, the difference here is that Sprint's CEO lied and said 4G would be free. If he had NEVER said that, I would not have that much of a problem with the fee....Although I find the fee justifiability arguments stupid.
On a single plan Sprint is cheaper, on a family plan, they are now the same as ATT. If you have two lines on the family plan with ATT at their cheapest rate it's 149.99. If you have two lines on Sprints cheapest family plan, with two EVOs, it's 149.99....