I'm not sure I can say what would make me walk away from WordPress but I know what makes me stay: trying out various CMS systems what don't even come close to WPs ease of use, if I can't figure out how to add a page to the menu of a site I wouldn't expect customers to use it. I recently had to update a clients TypePad based blog, I found the admin to be a chaotic mess and changing a template seemed to require republishing the entire site. It felt like software that had grown without direction. I like WPs admin, it's simple and it makes sense, if it ever stopped making sense then I'd leave.
Like someone once said "There are no new ideas. There are only new ways of making them felt." Personally I think the duplication of ideas is quite useful. How many times do you google something only to find the fifth or sixth link to be the one that explains the subject so it makes sense to you?