Personally, my use of fonts are more utilitarian. In that context, the fonts shipped with a typical Linux distribution are perfectly usable and far from shitty. While I would expect someone who has more of an eye for design to have more discerning tastes, I would be surprised if many people shared an opinion as extreme as yours or mine. (I suspect that they would be more inclined to notice the quality of font rendering or missing favorite fonts than anything else.)