If Bitcoin mining is becoming more and more impractical, what then? If Bitcoin mining is becoming more and more impractical, where you'll need to buy like a ButterflyLabs unit, and where even eventually a room full of these units might not be enough some day, what then?

Or, am I failing to understand some controls on Bitcoin that make it where eventually the processing power requirements go down again by some market factor? Forgive me, I'm new at this.
I think you misunderstand the problem. The reason mining is becoming impractical is because there's too much of it. It's like a restaurant that's too crowded. It means you can't get a table, but the restaurant is not going to go out of business.