WordPress offers free hosting under a wordpress.com subdomain. This option eliminates the need for setting up the CMS yourself and is reasonably secure, as WP uses multiple servers to back your site up. Additionally, for a fee, you can even set up your own custom domain name.
Wordpress by default allows commenting on pages, any page. Even if you turn commenting off for a page bots can still access the commenting endpoint; even if you use a 3rd party commenting system such as Disqus. Wordpress comes with an anti-spam filter called Askimet which does a pretty good job but
Tumblr allow users to customize their website with many built-in themes. In addition to theme selection, user can also further customize their website either through a customization editor wizard or through a HTML and CSS editor for advanced users.