"Browsers" are a good example of that. Often it's not the browser but networking problems, lost packets, latency, server responses, etc. Windows frequently waits 30 seconds when accessing network resource to tell you the resource is no longer available. Painful!
In my experience, fast code is usually beautifully written. Very logical and methodical. To be an awesome developer you NEED to be a perfectionist.
AND AVOID POLLING RESOURCES! Everything should be event driven. This is a concept very few developers truly understand. Events, events, events, events!
Agree that there's also a business case. However, $150ph developer who knows techniques is worth way more than 10 $15ph programmers because they implement the right solution the first time or make sensible decisions when taking shortcuts. Worth every dollar to find people who know what they're doing! You get what you pay for! (If you know what you're looking for!)