Niels,
I think to clarify Jean's point, when you buy a 300mbps circuit, you're paying for 300mbps of internet access.
That does not mean that a network should (and in this case small-medium ones simply can't) build all of their capacity to service a large number of customer circuits at line rate at the same time for an extended period, ESPECIALLY to the exact same endpoint. It's just not economically reasonable to expect that. Remember we're talking about residential service here, not enterprise circuits.
Therefore, how do you prevent this spike of [insert large number here] gigabits traversing the network at the same time from causing issues? Build more network? That sounds easy, but there are plenty of legitimate reasons why ISPs can't or don't want to do that, particularly for an event that only occurs once per quarter or so.
Does Akamai bear some burden here to make these rollouts less troublesome for the ISPs they traverse through the last mile(s)? IMO yes, yes they do. When you're doing something new and unprecedented, as Akamai frequently brags about on Twitter, like having rapid, bursty growth of traffic, you need to consider that just because you can generate it, doesn't mean it can be delivered. They've gotta be more sophisticated than a bunch of servers with SSD arrays, ramdisks, and 100 gig interfaces, so there's no excuse for them here to just blindly fill every link they have after sitting idle for weeks/months at a time and expect everything to come out alright and nobody to complain about it.