Updated 20-Sep-2023
Two very popular content management systems are in their teenage years now: WordPress will be 14 this year, and MediaWiki will be 15. Those are a lot of years on the web. As teenagers, these two successful and interesting projects try and act like the adults they want to be. Unfortunately, this can lead to an obsession with trying to live the high-life, and model themsleves after their adult role-models. Sadly, many teens don't have great choices in whom they look up to, adulate, and emulate. Teens tend to try and grow up too fast and focus on the wrong things, get obsessed with fads, and judge themselves by external factors that have nothing to do with their own success, or happiness.
Teen WordPress
WordPress is very chatty, focused on a visual editor, and real people (by that they mean not nerds). But nerdy cool is what got this teen to where they are. In fact, using nerds to do the design work gets you, well, something not very elegant, nor usable, and half-broken. Read the scathing report (and deep background) on the WordPress Plugin Repository Revamp. And so while WordPress has nerd roots, these are not taken very seriously (other than letting the actual nerds try and figure out how to engineer and project manage what they don't understand), and horribly outdated development workflow is still the norm. In addition, plugins like Hello Dolly are still the default install. This is because Automattic is run by teenager.
Teen MediaWiki
This teen still has deep rooted editor and uptime bias. That's a good thing. But let's look over one of the technical teams. It appears that reader has many designers and two programmers? And the parsing team, that is the only one that can actually help extend most extensions, including reformatting for different formats (such as ebooks), few resources indeed.
Here is a great example of what is wrong, namely lots of academics with no sense of urgency. A Summer of Code contributor from 2013 has already implemented annotation functionality, and we get a group of deep thinkers coming up with... nothing. The wrong people are being hired at Mediawiki, certainly in terms of important functionality like basic annotation.
Instead, MediaWiki is focused on growing an organization (not improving what they offer, or the user experience). This is again the same teenage obsession with something other than what one is doing right now.
One obvious problematic for MediaWiki is the visuals. This is odd for a teenager to not tune in to. Wikiwand, a 2013 startup which is now a team of 10 has produced a skin for Wikipedia and catapulted themselves to a ranking of 1,500 on the web.
User Experience
There is so much to improve in the core user experience of both of these successful products (which I deal with daily, as a user and sysadmin). Indeed, this gloss is in need of much more detail, but it is a start to say that focus has been lost, and in not a good way.
Money and success can cloud judgment quite easy, especially to the teenage mind.
Sclerosis
The danger here, beyond simply misspent youth, is that a sclerosis is setting in regarding basic features. That is, meaningful change (technical, organizational) is becoming out-of-reach for these crazy kids. Opportunities are being missed.