Some of us aren't bothered by this at all. Some are.
Those of us that are, include those running 2 WoW copies at different resolutions (multiboxing), or simply just change our UI size, or copy our addon settings back and forth between two computers, like for instance desktop and laptop.
Some addons play very nice with changing scales and aspect ratios. Others.... not.
Please consider giving your frame position saving some thought; LibWindow does it right. If you want to use it, use it. Or just look at its code and use the same methodology.