Ask HN: What is your professional opinion of Wordpress?

My last job was at a hosting company where all I did was help fix Wordpress issues. I'm trying to learn how HN views the strengths and weaknesses of the platform. Also, if you know of any resources to know Wordpress at a very in depth level. I know the fundamentals of setup, picking quality themes/plugins, customizing pages/databases, and setting up hosting but not much beyond that.