@calcifer Comcast used to prohibit having multiple devices connected to a single IP address on a residential account, but this was unenforceable and widely bypassed, and they later permitted it. Later Comcast prohibited running Internet services on your residential account, but this was also unenforceable, and later permitted.
So I can imagine someone still believing old rules were in place.
Also with software bloat, many people don't realize how little it can take to run services.