I've made use of Yodlee so much so that over the years, I've told it to anyone within earshot. The most common excuse I get from even the tech savvy programming crowd is "I do not want to have all my account information in one place, it's a single point of failure".

While true, the same holds for all information that we have online that is important to us. But it's a big mental block that both these sites need to overcome. Yodlee kinda shifted that burden by selling software to financial providers whom we already trust by opening accounts.