I've never heard of that kind of network, is that a US thing? I can't imagine having my traffic routed, as the person I replied to said, to the other side of the country before being routed to the proper destination. That is so incredibly inefficient and unnecessary. Not to mention the single point of failure.

Edit: And it makes hosting a public facing server at home a nightmare... I see no benefit to this except not having to get a large IP range to properly assign them to your customers, which sounds like capital efficiency rather than decent user experience. Did I get it right, is this a US thing? :D

Edit 2: And there are a lot of systems IP-banning abusers (it is, in fact, one of the most basic recommendations), meaning that if someone sharing that public IP gets IP banned, the entire customer group sharing the IP is troubled. Even worse if it ends up on a shared blacklist...