Only 91% of households, really? HDTV penetration is much larger than that and more importantly, something that a lot of people don't seem to understand, there are SDTVs (those are the 480i ones) that have component connections (like mine for example and my best friends and hell even my grandmothers RCA tv with the old style curved glass that she bought last year has them too). This is what you're missing, component isn't some super-niche thing as you and others tend to believe. Combine that with all the tvs with at least S-Video connections and you get a real large piece of the pie chart that has a connection or connections that are vastly superior to composite, and yet as of this moment Nintendo doesn't seem to be offering these cables in an easily accesible manner.
Instead they seem content in having us (hardcore gamers, the ones more likely to want the best possible cable) jump through hoops to get them at launch instead of the way it should be, at the store for me to pick up with the Wii. And sorry but that whole "retailers don't want the component cables" sounds like some damage control spin cooked up by the PR staff. There are many more Wiis than PS3s available and yet all the reserves got filled out very fast, so the demand is clearly there at least throughout this holiday season, no reason to hold back some accesories that they will sell by the end of the year.