Companies who spend millions of dollars on transaction systems, and those systems are at the core of processes which generate revenue, DO CARE that it takes 5 seconds instead of 10. And that's why chip people will go to great lengths to optimize chips. Because they sell better than chips that aren't.
As for programming optimizations ... Maybe you spend 40 work hours squeezing a 3% performance gain. Now if your system is being used by a lot of people, and for something "important", you're going to leverage that 3% with every user who saves that time. Given a decent user base, you're going to get that 40 hours back pretty quick.
People who are trying to make more money by using your software are very concerned that your program does it's task correctly in the shortest time possible.