I really don't understand what your point is ... how does avoding load on the internal backbone leave which costs of growing the backbone to the ISP?!
> The point about torrents and bitcoin is that these applications are particularly burdensome on routers because of the amount of connection requests as compared to a fairly manageable HTTP or RTSP session.
Uh? How is the number of connection requests relevant to a router?!
> As I mentioned above, server co-location and direct network peering is already a thing that many larger ISPs offer on a non-discriminatory basis.
Non-discriminatory is no enough, it has to be free or at cost. They are a monopoly, and as such non-discriminatory is still a monopolistic price.
> However, most new businesses will piggyback on existing cloud hosting (AWS/Google/Azure) or CDN (Akamai/Google/Cloudfront) arrangements.
Which isn't necessarily that bad, as long as there is competition among CDNs. A CDN ultimately is just a different kind of transit provider.