In all honesty, this is one of the less abused quotes, and I have seen more benefit from it than harm.
Like you, I've seen people produce a lot of slow code, but it's mostly been from people who would have a really hard time writing faster code that's less wrong.
I hate slow software, but I'd pick it anytime over bogus software. Also, generally, it's easier to fix performance problems than incorrect behavior, especially so when the error has created data that's stored somewhere we might not have access to. But even more so, when the harm has reached the real world.
> I have seen more benefit from it than harm.
Same. I, too, am sick of bloated code. But I use the quote as a reminder to myself: "look, the fact that you could spend the rest of the workday making this function run in linear instead of quadratic time doesn't mean you should – you have so many other tasks to tackle that it's better that you leave the suboptimal-but-obviously-correct implementation of this one little piece as-is for now, and return to it later if you need to".
I don't believe there is any tension at all between fast and simple software.
We can and should have both.
This is a fraud, made up by midwits to justify their leaning towers of abstraction.