As you referenced that bug and there also gave an example involving fractions and =0.1+0.2 you would certainly also agree that the binary floating point representation of =0.1+0.2-0.3 is not 0.0, still Excel displays 0 as result (and so does Calc) instead of 5.551115123125783E-17 because users expect that.
Your bit-level accuracy approach isn't as simple when it comes to user experience and Excel compatibility.