While that is true the current state of reddit UX allows them to succeed by virtue of critical mass gained before they went nuts. If you created a new site with that UX you would get nowhere.
The simple truth is people are drawn to websites for what they get out of them.
I recall being turned off by Reddit's UI when I stopped using Digg. The content was so incredible that I learned how to love it. And now they've killed Apollo so my only interaction with it is via Google search results for my problem du jour.
This has other reasons though, like the fact that this site has better moderation and better users in general.