``Development speed is what counts, not execution speed.''
If you have a program that executes once a day, and which takes 25
hours to run, execution time is important.
Small programs are run once. Big programs (applications) are run
many times.
Speed does matter, just ask your girlfriend. The difference between
2 seconds and 3 seconds is, duh, 1 second. Do that 100,000 times,
though, and you've got over a day being wasted. Not every speed
problem is the fault of a poor algorithm.