I understand the framework is very open, plenty of plugins and makes life easier. But is it really that good when it comes to long term viability? To me wordpress is more of a stage 2 product. It meets costumer needs. And I believe the reason it has become so popular is because of how easily people can setup their sites with it. Sometimes we sit down with clients and out of nowhere they are like; Oh we want it to be on wordpress, and we are like; Noou you dont. I have had cases where clients are not satisfied after they apply an update to a plugin and disrupt all of the customized features. If it's for a professional solution, do you think wordpress is the best choice?
Only for the blog portion of the site. It is my opinion that WP made a critical error when they didn't maintain separation of logic and structure.
It is easy to build professional website with wordpress. But if you want to keep it for long term, then you need to understand deeper about how wordpress work, else you need to have a professional programmer who understand about wordpress API.
Building simple informational (business or personal) sites in wordpress is really a good choice compared to other options.