(...) "premature emphasis on efficiency is a big
mistake which may well be the source of
most programming complexity and grief."
Note: not "optimization" but "premature emphasis on efficiency" and "may be the source of complexity and grief" not "root of all evil."
Who invented "root of all evil" then?
Edit: here it is, also Knuth:
" There is no doubt that the grail of efficiency leads to abuse. Programmers waste
enormous amounts of time thinking about
or worrying about, the speed of noncritical
parts of their programs, and these attempts
at efficiency actually have a strong negative
impact when debugging and maintenance a
considered. We should forget about small
efficiencies, say about 97% of the time: premature optimization is the root of all evil.
Yet we should not pass up our opportunities in that critical 3 %. A good programmer
will not be lulled into complacency by such
reasoning, he will be wise to look carefully
at the critical code; but only after that code
has been identified."
OK, there it is, but nicely guarded in a long sentence and not made to be used as some mantra!
Additionally, I agree with Joe Duffy:
"It's an all-too-common occurrence. I'll give code review feedback, asking "Why didn't you take approach B? It seems to be just as clear, and yet obviously has superior performance." Again, this is in a circumstance where I believe the difference matters, given the order of magnitude that matters for the code in question. And I'll get a response, "Premature optimization is the root of all evil." At which point I want to smack this certain someone upside the head (...)"
I think the idea of not optimizing for efficiency is a good one, but (like all things) can be taken to extremes. If you consistently choose the slowest way to do something then when you are ready to optimize for performance you'll probably have problems. What do you do if after the bottle necks have been removed, the system is still too slow?
You may not be one of the "many programmers" but I certainly have worked with enough of them over the years to know just how pervasive they tend to be.