That said, I'm in agreement that most devs don't know much at all about performance. Frankly, we're told not to... it's a sad state. Performance is explicitly referred to as a last priority, the "optimization is the root of all evil" quote is completely taken out of context and parroted everywhere (go look up Knuth/Hoare's context if you haven't), etc.
All that is to say, the issue is not specific to education but is an unfortunate part of engineering culture. We, as a large group, explicitly neglect performance and treat it as a dirty word.
IMO we need a sort of performance revolution the way testing got one. I've written lots of software in a 'benchmark driven' way, and the results are extremely fast programs - I've gotten programs down from just under 1ms to a few dozen nanoseconds like that.
I don't think scalability, portability, and clean code are the enemy.
C/C++ are as portable as they ever were, and Java/.NET provide higher-level abstractions that work across both Windows and *nix systems. Even Electron doesn't have to suck, in theory.
The reason performance is bad these days is because developers are just bad. The number of developers doubles every five years. Ergo, half of all developers have less than five years of experience. The vast majority of them don't have a CS, CE, or EE degree. A large number of them went through bootcamps (which are an expensive version of the old "Learn VB in 21 Days!" books.) And they're all writing the Electron apps we love to hate.