Why do you want to attract uninterested users who's interested are primarily superficial and not aligned with the core values and spirit of linux/foss? This is how you breed corruption.
I'd argue that your comment is somewhat elitist - what does it even mean to say that someones interest are "primarily superficial and not aligned with the core values and spirit of linux/foss"? Plenty of linux users already care about how their interface looks, that does not mean that they don't care about open source.
I guess I'm obliquely commenting that keeping the project small and in the hands of open-source developers, may be pointless. Otherwise, why agonize over what others are doing with it? Either we want others to use the open-source version too so its a popular desktop with lots of attention, or we don't and becoming a popular desktop with lots of attention doesn't affect those open-source die-hards at all. Either way, a successful project becomes popular on a lot of desktops.