I say, come on, be realistic. This is not a practical thing you're building, it's a fun project that happens to work too.
It's like building a model airplane. You don't do it because you need to fly across the country tomorrow in under 6 hours with drink service and a nap, you do it because you can and it's fun.
What's impractical about it? It's very cheap and easy, and hey, maybe you don't need a faster file server. Hell, some of us with the money and expertise to setup an uber-NAS go with the Pi precisely because it suits our needs just fine.
It's like building a model airplane. You don't do it because you need to fly across the country tomorrow in under 6 hours with drink service and a nap, you do it because you can and it's fun.