Even this DDoS attack is still drastically smaller than Akamai's purported bandwidth. The whole point in their network is that they're supposed to be so distributed, with so much bandwidth that withstanding even this should be trivial - they claim to serve upto 30% of the world's daily requests, their network has a capacity of 30 Tbps and they're bottling it in the face of a 0.6 Tbps DDoS attack.
This was really always Akamai's selling point - precisely that they do have far more bandwidth than any DDoS will ever muster. DDoS protection is in fact one of Akamai's single largest selling points - it's plastered all over their site, so if they're now saying they can't be bothered to deal with them then again, what's the point in Akamai?
So sure you're argument makes sense for a provider that doesn't own a colossal amount of bandwidth, but you obviously don't know Akamai else you'd realise your entire argument is moot in relation to them because they're not short on bandwidth. You argued that you can't ever win against DDoS attacks unless you have more bandwidth, and, er, well, they do - by a massive margin and the chance of anyone building a bot net with the bandwidth to rival Akamai's capacity is basically zero.
Taking the DDoS on the chin, which they could trivially do even with existing customer commitments whilst working with ISPs to deal with infected machines would've been a massive benefit for InfoSec (and been great for their profits as it would let them boost their reputation further and reduce future impact on their network). Instead they've decided to act with the attackers and tell the world they can no longer be trusted on their main selling point.