If you drop your fees so low your customers get pissed, well then, you'll loose customers. Or if you can't afford to maintain infrastructure, then you'll lose customers due to your unreliability.
A race to the bottom is the reason we have 60" flat screen TVs that are better quality and cost a fraction of what a similar TV cost 10 years ago. It's a good thing.
The race to the bottom in the airline industry was entirely driven by consumers who were willing to put up with crappy seat just to save $10. They got exactly what they wanted.
That said, we are seeing a shift toward premium economy. Basically some airline said "I'll bet there are some customers will to pay more to get more" and they were right.
HN likes to talk about the "race to the bottom" as some failing of capitalism, when it's actually working exactly as it should. "The market" doesn't get it right every time - plenty of companies make the wrong trade off - but the consumer is the ultimate decision maker if the tradeoff is worth it.