Truly no one else in the entire world knows this legend or how to assemble the crown? Seems lazy.
*Bonus Points - The 24 unusual gems quest.pretty annoying you can only do it if you join the TG. Also the people live in perpetual misery. However, everyone down there is essential almost and there is little you can do. I can't imagien a self respecting hero would do either. Your options stand at 1) Join the TG, do illegal and immoral stuff, make people's lives worse or 2) Ignore it and pretend it doesn't matter and it kinda doesn't mean much without you helping build it up. In reality, you should be able to go down there, murder every last one of them, boot Maven Black-Briar in the ass (or maybe not that but at least knock her down a couple pegs) and make it a better place for everyone.
There is no way to really save the people from the crap they put up with and the Thieves guild nonesense. It always bugged me that Riften is essentially a lost cause as a good guy. Not sure if this was covered anywhere but I can't find it.
