I was thinking about it and if nobody can beat big ben alone in marleybone, it should give way more xp and gold.
Sorry, you couldn't be more wrong. For four years now, I have soloed this dungeon. With a wizard or two I used henchmen at the end, but that's it. The XP is fine, as are the drops.
Please don't try speaking for everyone - this is not difficult to solo at all, it just takes time.
I soloed it on all 6 of my wizards. I can't speak for since I never did it with that, but I didn't have much trouble on any of my wizards except probably my first time through. But that's really just normal learning curve.
Even if it's possible to solo, its a lot easier with a group and Meowiarty isn't much of a final boss. The game does encourage teamwork and it's not a particularly hard dungeon with a group.
The only trouble I had with this tower was on my storm, but she was only level 25, not really high enough to try to solo the place. The new Team Up option makes it easier to find people to run through this with. The first time I soloed on my Balance, I bought a health elixir, and that helped out a bunch.