Hahaha true!
Anyways, I agree 100% here, but to offer some excuse I think WriteFreely/Write.as is still a very young very small project, and the very instability behind the existing themes looking different/not-quite-right/broken is probably exactly why not much has been invested in fancier themes as of yet: the platform is still evolving too much.
From conversations I’ve had with matt, the theming engine may be getting an upgrade this year 
, so when that happens I think it will be only natural that we see the development of a more flexible and powerful theming system possibly like Ghost’s handlebar themes and from that some much nicer themes. Once the backend gets there, it will happen!
As a sidenote, I wonder if at some point it would make sense to have the frontend rewritten in Elm, which also supports PWAs and would bring WriteFreely/Write.as into the interest of a flourishing frontend developers community 