I would argue that Wordpress is a great example of how something doesn't need to be "well-engineered" (when it comes to abstractions, maintainability, etc) to b

I would argue that Wordpress is a great example of how something doesn't need to be "well-engineered" (when it comes to abstractions, maintainability, etc) to be widely useful for many. Although I think the exception there is security (and yes I know many will say clean and well engineered code is secure code). Security has to be solid or it will impact too many people negatively.