It does though, at least indirectly. If the point is to handle different screen sizes and resolutions properly that also has the side effect of handling window resizing; and if one doesn't work correctly the other will most likely have issues as well in some situations.
You can pick apart words and meanings as much as you want - a UI that stops fully functioning after the user makes a valid input I consider it broken. Hopefully you wouldn't call it "working as intended" either when a site becomes unscrollable, freezes up or literally moves sideways out of the browser's viewport when you type in a text field.
Resizing a window is not a weird edge case, it's been a basic UI feature for decades, supported even on some smartphones and tablets, and desktop applications have been able to handle it fine.
Intentionally broken is still broken.
Oh bullcrap.
This is just a rationalization from people who like the shiny.
> it is staggering how easy it is to break many of those sites just by resizing the browser window.
I should say that a responsive website does not actually mean a website that responds to resizing the browser window - and that should not be taken to mean it's "broken". Saying that makes you sound like a typical sweatshop PM or stakeholder :) - i won't belabour the actual meaning here.