I'm probably going to get killed here from lack of knowledge amongst brilliant minds.
I have been digging through this thread as a very frustrated phpBB -->
END USER<--.
I have been involved in Forums for a year now (only with phpBB). Remember, this is an End User perspective, please remember that, you smart people . . .
I'm "that guy" that has the dream of starting a Web Forum and thinking it's going to be easy. The guy who thinks his biggest challenge will be keeping members from fighting and fear you will have to ban someone. That has not been the case...
I chose phpBB because it is the best free Forum out there (I spent months to determine that), as for a lot of people, you are not sure if you are willing to invest in software in hope to build a Forum that others will follow. After a year I have 430 members and I'm pretty proud of that, as I chose a pretty competitive market, Mountain Biking.
My Site:
http://www.imtbtrails.com
As an End User, I'm the guy who has had to take a Forum platform and modify it to meet the social acceptance and needs of the user group, it has been a nightmare in some instances. Spent several hours just last night trying to search phpBB help forums as to how to enlarge the font size in the body of a topic because it was a member request that made sense. Hours! Remember . . . End User. I'm not a programmer and didn't even know what .php was when I started. I wasn't even sure of how to phrase the question if I had to ask for lack of finding the answer. Even then I pieced together a couple of forum responses . . . guessed . . . made the change, hit submit while squinting my eyes in fear the site would implode!
END USER...
1> Someone that most likely does NOT understand programming
2> Someone that barely understands FTP
3> Someone that asks a million questions about the most basic things
4> Someone who thinks they will spend most of their time moderating as oppose to self software development
So, why NOT CMS? WordPress is a CMS and is the largest most successful Public software I believe out there. Plugins sound a whole lot better than Hacks and Mods. Plugins take all the work out of modifying code. I HATE modifying code!!!

It's hours of guessing, failure and repeat.
Remember . . . End User?
I want to talk about Mountain Biking with the members, not how do I customize my Header...
There are some that want to get under the hood and wonder how it works, then there are those that want to just stab and steer (but we do want to be able to choose the color, add "Thanks", have an Event Calendar, etc. etc. etc. just like when you go to the dealer to pick your car)

.
If you truly want to make phpBB the greatest free software out there (like WordPress), then make phpBB a Plugin based system where you would invite others to produce Plugins that add awesome features (LIKE AN EVENT CALENDAR!<-- This is me yelling in desperation

). There is a lot of free plugins out there that are motivated by developers who offer premium plugins for a price to keep them motivated to create free plugins.
Despite the "Unpaid Developer Philosophy" that the core of phpBB seems to be so proud of (no jab intended), free enterprise is still alive and well in America. You can motivate thousands of people across the globe to invent cool widgets, awesome plugins, and amazing features that make phpBB user friendly with intuitive actions.
OR...
Does the phpBB core circle have this purest mentality that it's Forum "ONLY FORUM" philosophy?
I hated the idea of "Dropper Seat Posts" on Mountain Bikes, for 5 years since they came out, I bashed them. Thought it made you less of a Mountain Biker, reduced your skill level, called it a crutch! Then I finally bought one and found it to be one of the funnest things I have ever purchased. I can do more than I ever could without one...having a blast. Ate my words publicly.
Bottom line...
Yes, long rant...Think about the End User.
People that want to start Forums don't want to write code, they want to have a forum, interact with their kind, and possibly make a couple of bucks off direct advertising and Google Adsense to at least break even. If I want to change my header image I don't want to dig in to the right .php file and change something that has potential failure. I want to upload my image and switch it out like WordPress, is that too much to ask? Or did I just kick a beehive with the wrong Forum Developers?
Think about the dumb End Users like me...
