I don't disagree with your assessment, but I do think 'open source project' is way too vague a concept to really draw conclusions from. In the case of Wordpres

I don't disagree with your assessment, but I do think 'open source project' is way too vague a concept to really draw conclusions from. In the case of Wordpress, I think a big part of its success is that it is built on the most well-supported technologies on the web: PHP and MySQL. I'm by no means a great programmer but it was relatively straightforward to migrate a Drupal site with a completely different DB structure to a Wordpress redesign. Both use PHP and MySQL. In contrast, my built-from-scratch journalling tool that runs on RethinkDB will take a bit more work - all over the place - to work with some other database (probably Postgres, SQLite or MySQL). It's still relatively simple, but less so than the Drupal->Wordpress conversion. My Horizon app, on the other hand, will basically have to be rewritten if support and development were to stop.