Both the upstream and the downstream systems were shared among the 250 or so homes fed from a fiber-optic node, and the performance of your system was related to what your neighbors were doing with their Internet (this is still the case). When DOCSIS was standardized, they started with the Motorola QAM system. The whole cable system is tailored to deliver information to a home, with a very limited upstream, which is the exact opposite of what's needed for a high-bandwidth server (which needs relatively little downstream and a very large upstream.
Internet as originally provided outside of dial-up was expensive (I was paying $700 per month for 1/3 T1 in the mid-nineties), and the phone companies were pocketing a large amount of money from business customers who were buying Internet OR connecting their facilities with frame-relay. When home DSL became available, the telcos didn't want to cannibalize their business service, so the no-servers, home service tiers there are protecting the (now significantly cheaper) business tier cash flow.
I had a rack of servers in my basement that were Internet connected, and I can tell you that for outbound services (web content etc), my customers/readers/users get much better performance being served by a single $20/month Linode server than they ever did through my line-of-sight microwave connection. Even beyond the last mile, the distribution plant isn't a place for anything but a hobby server.
Then the big telcos got the game, and started to elaborate among themselves how to remove service and add fees.
Someone saw the non-commercial vanilla clause, and had the great idea of using that premise to shut down inbound connections by the most insanely idiotic assumption that a listening port is a server which is foolproof indication that you have a business.
Then everyone move to the telco that didn't do that, free market at its best. for about 6 months. until all of them did. nobody had any option. and here we are today.