- Look for a famous template

- Rewrite it in bootstrap

- Get it approved

As of 2016, the front-end ecosystem has grown big. Material Design and other UI/UX innovations (fancy modals, fancy sidebars, scrolling animations, etc.). This causes the market/buyers to look for themes that will allow them to look like the next AirBNB or Google. Theme marketplaces are looking for bootstrap/foundation templates jacked full with these javascript libraries and fancy stuff, increasing the barrier to entry for stuff to get approved.

Here was my experience writing a template last year:

I spent 2 months of weekends and weeknights to scout out the competition and worked on an admin theme. Made it with fancy charts, animations and a few javascript libraries embedded in that the market would probably want. I proceed to try and get it approved. Then, I found out I'll have to fight through other big agencies that crank out these themes like pancakes for a living while they price it 20-30% lower than mine. These agencies also sell these themes in other marketplaces that make them very popular choices over others since they can support customizations and what not.