I am hoping OP will clarify his requirement a bit, since he hasn't provided a lot of information and his post seems contradictory. (Unless he's not 100% clear on what a NAS does, which is certainly possible.)
Generally, I think folks need to consider (a) how many computers they need or want, (b) the need for a household Ethernet (if we are indeed talking about "home" situations wedded with "enthusiast"), (c) their backup requirements.
I have several friends who've leaned more and more toward "mobile" access, but they have desktop computers. Few or none would consider having a household LAN. They probably use cloud-based backup solutions, or they have external USB-attached storage for backup.
At some point, a home user with more than one household user and at least a few computers may incline toward some cable-drops, one or more switches, and a router. I'm pretty sure all of my friends have routers if they bundle their internet ISP services with cable TV or telephone; nobody would be clunky and stupid enough to use dial-up ISP services.
Some folks might begin to think about using one or more of those four wired ports on their internet router -- for storage, by example.
I just cannot imagine my friends having the patience to manage a digital fortress such as mine. They probably don't have the time. Other folks may have exotic needs that lead them to acquire more in-home storage solutions.
I would've simply got myself some NAS box with a built-in OS or GUI, but I want to do more things that I could better do with a server. I started simply by re-deploying old desktop hardware. Even my new (under development) server came from some surplus parts, but the drives and storage controller were chosen deliberately.
The biggest thing that concerns me at the moment until I can retire my WHS box is my power consumption. A lot of folks and relatives to whom I'd suggested the possibility of a home server backed away from the idea of leaving a computer running all the time. I think there are some options for having managed sleep states or machines that wake up when they're accessed. But most people wouldn't want to fiddle around with such things.