For instance: what is an HTTP server and when/why would I have one? And, similar discussions for the other services.
I choose to run a couple of websites. A web server must provide the information of these sites. The web server which provides this information for me is Yahoo. I couldn't run these sites from home because of throttling.
If throttling didn't exist then I would still subcontract websites. I'm sure not going to get up a few times each night to save $100/year in security.
If you need to get into your site remotely then set up an ssh key or an ssl certificate. Yes there will be 1000+ people each second trying to guess a password - far more if you have a router. No-one will guess a key or certificate.
Many of us get a cheap router and use that between the modem and computer - wired. My $38.00 Linksys has worked well for years. It's 300 days up-time, now so obviously I don't spend time on it. Anyway a person who gets the correct router can put third party firmware on it and set it up as a firewall. I'm connected to my router via cat V. cable Of the stuff which gets by my router firewall - and is then caught by my machine Firestarter Firewall - only 2% is interesting.
A person can be power-saving and get a plug computer - or they can just get an old computer from the dump and refurbish. If a person puts their webserver/bit-torrent/FTP machine on the far side of the firewall then their actual computer is not threatened. That being so and servers on the Internet being taken over due to lack of patching - I'm not hearing anyone here saying that their PCLinuxOS computer has been taken over lately. If I ran Windows then I'd probably want a security appliance such as Astaro - and education of everyone using the box. But - a person can fire up an old box on the network and just do banking. If it's a Linux box then it will require a password- and at an hour a month it won't be more than a problem with space.