I guess sensible defaults is what Elementary wins on. They have actual designers and UX guys working on it. KDE, by default, looks quite bad. It's the usual Linux issue, where you have great coders but no designers or interaction specialists.
In Elementary you can just install it and get going. It'll look great and work great, without you having to configure a ton of stuff manually.
That value is very important to a lot of people, the people who don't want to or can't spend a lot of time configuring things themselves.
I agree, imagine someone meeting linux for the first time. Their first impression can be "-damn that looks ugly and complicated" -you can customize it! "-well that sounds complicated too" or "damn that looks userfriendly and sexy" "-hell yeah!", i believe that was the only thing limiting linux as a mainstream os, ubuntu was cool once, but they ######ed it up. EOS looks a lot like osx really, but thats not a bad thing.
Eos is what linux needed to attract new users. Period.
Noone wants an ugly baby, to fix him later. everyone want it to be cute out of the box... or the ######.