It's because the scale is small. The size is set to 80x80 pixels, presumably for icon exporting. However there's nothing stopping someone from opening it inkscape and exporting a PNG at 12000 DPI (which results in a 10k x 10k raster resolution). I don't think the logo scale should be so small and I don't think browser should have such limited zoom capability. I place the most blame on the browsers though.
This always differs by people. I thought Samsung pretty clearly swiped the Apple look with the early versions of Android. Even beyond the rounded corners. Sure, it isn't a pixel perfect copy. But I do think inspiration was drawn, even if not intentional.
I have a bunch of icons in my dock and the only two that look similar are browsers. (I hacked up a copy of the Edge logo from the article and slapped it on a applescript to put it in my dock)
These comparisons will be made all over the place, since these designs are always inspiring each other. When I see the new edge logo, I see something that resembles some of the unused branding of the Xbox One and Xbox360, something that resembles the Firefox logo, something that resembles the new design direction of the office suite, something that looks a little like iOS gradients, something that looks a little like the Chrome logo, and so on. I'd say it looks a lot more like old Xbox branding than Firefox branding, though.
https://upload.wikimedia.org/wikipedia/commons/3/30/Firefox_...