Remember, the key to all the chmod'ing is to allow your webserver user the ability to write to logs/, backups/, public_html/backend, public_html/images/articles and public_html/images/userphotos. If your files aren't owned by the webserver or don't belong to a group that the webserver user belongs to then chmod 775 will not work. If you are on a hosted environment you may have to chmod 777 if you can't chown -R <yourusername>:<webserveruser>.
The reason people blame things on previous generations is that there's only one other choice.