Yeah, in an attempt to be concise, some nuance was lost - I think Wordpress as a pure editor, as a real CMS, when set up properly and/or using an OOTB template is perfectly fine. The post editor is good, you have all the basic formatting elements, page types, etc.
But I think that limits you to two universes of setups - either built by a "pro" (for some definition of pro) who configures everything, installs plugins, installs and customizes the templates and basically gets everything perfect OR very basic cookie-cutter installs with lots of limitations.
Either of those scenarios is fine, and I think it's great to have an ecosystem of small designers whose customers are DIFM users. I agree for "blog authors" and writers it's also fine, subject to the above limitations.
The reality, though, is that market is tiny - "tens or hundreds of millions of users" - I do not think there are in the hundreds of millions of blog authors getting active traffic, though I maybe buy "10s of millions". Tumblr alone has 500+m active sites, even if we assume only 10% get actual consistent traffic (which would be roughly consistent with the data I remember), that alone is 50m active sites. If there are 10s of millions of bloggers, we would expect that the active # of sites are in the single-digit millions.