Inkscape is implemented as if things that render the same (or just similar even) are the same too, thereby destroying clean code. Which is wrong and makes it near useless for coders, heavily frustrating the number 1 strong point of SVG: letting coders and clickers cooperate.
If i use Inkscape for adjusting 1 thing, i want the SVG code of only that 1 thing to change, not have lots of my SVG code changed just because of some internal representation or convenience for the Inkscape implementors.
4 lines together visually forming a square, is not the same as a real square. A name/value attribute pair can sometimes by SVG specification be replaced with some CSS, but even that makes a difference in semantics. And with SVG support usually being partial, it often also makes a difference in rendering.
Cheers,