As a developer (not of the Ghost blog), I probably understand why it was not added - because there is always something more important in the roadmap.
But if guys will combine this request with another one like an ability to break one line to a two, three or four panels/columns with ability to aling text - it will make Ghost more attractive to the new users.
Each time I write my articles I want to place image on the left and text on the right in the same line.
Even remembering that I am a developer - I am lazy to write a code when I switched to write a text.