Not knowing how to get Plone to look 'like you want' is probably 'scaring away new users'.
I think 'adding galleries' and 'bling' is important to get new Plone users.
Mosaic is a big step forward, so I would love to see for example:
a) A 'page layout' Mosaic editor (where one could place the navigation, search box, logo, etc.
b) A 'images (gallery)' tile where one could choose or upload images
c) A way to add css classes and/or animations to (some) tiles.
I have been trying to do b) myself ( with Tuple, Datagridfield and plone.formwidget.multifile ) but it looks like it needs 'a different approach to work')