@mpiotrowicz can you have a look at the default customer account templates Shopify generates? https://github.com/Shopify/shopify/tree/master/db/default_asset_values/templates/customers
We don't want to stray from that too much. We would much more improve things at the source.
Ideally, a theme will not even provide any customer account templates, just CSS for them. The customer account templates are optional in the theme. And not having them present does not mean that they are not used, it just means they are not physically present in the theme ZIP and in the Template Editor, and that markup generated by Shopify is used.