This is not about the size of some content provider, but about not providing the service they bill their customers for. The DSL subscriber pays for an internet connection at n Mbit/s. Note: The DSL subscriber does not pay for a line to their local central office, the product telcos sell to end customers is internet access. Now, these customers who have bought internet access request some data transfer from some server at Hetzner (for example), and Hetzner essentially says "here, we have a few gigabytes of data for your customer, where should we drop them off so you can deliver them?" - and the telco's answer is "we won't, unless you pay us!"
This is not about moving the data to the telco's network, but about the telco delivering the packets to their customers. Cost-neutral peering does not mean free peering, those "content providers" complaining about net neutrality violations do not complain because they have to pay for a line from their datacenter to some location where the DSL telco's network is, so that they can interconnect (they generally are more than willing to pay for that, at least if it's not some location where the respective telco is the only one who could provide the line and would bill unusually high rates for it) - what they are complaining about is that, essentially, even if they were to offer delivering their traffic directly to all the central offices of the telco using their own lines, so the telco only would have to connect them to the DSLs of their customer, those telcos would refuse unless they were paid for it.
And I am not exaggerating: There have been cases where CDNs offered to place cache servers in the telco's network, to pay for the rack space and the power and their servers at normal hosting rates that other hosting customers would pay, so that the traffic originates as close to the subscriber as possible, thus reducing the network costs for wide-area transport by the telco as much as possible, and they refused.
They want to be paid for access to their customers - nobody would complain if they wanted to bill for wide-area transit at normal market rates, or even if they wanted to have the traffic delivered closer to their subscribers, as long as the content provider could choose their transit provider freely, thus buying the transit at market rates. But in practice, they want to be paid unless you installed your own DSL to their customer.
Also very interesting, though german only, unfortunately: http://netzneutral.init7.net/de/situation-init7.php - they report that they tried to get an offer from DTAG for direct peering, and what they got not only didn't match what they requested, but also had progressive pricing: The more capacity they would have wanted to buy, the more they would have had to pay per unit. That is to say: a 10 Gbit interconnect would have been more than 10 times as expensive as a 1 Gbit interconnect. That certainly is not due to costs, hardware for bigger pipes never gets more expensive the more you buy.