Perhaps I'm just rusty but age has only made me cautious. I'm responsible for a rather large and complicated UI framework that we use internally. The thing I've discovered over the last 5-6 years is that APIs are volatile as are JavaScript libraries, browsers and security concerns. It's terribly hard picking something that you can rely on. Even jQuery has enough breaking changes for me to have a week long task getting past 1.4.2 on our product. We have over 400 complicated web app pages that need testing to make sure we haven't broken any edge cases.
The learning curve is tough, the maintenance is tougher and the churn is terrible. It's a living hell on a large project. It makes me long for WPF or even Win32 where 20 years without significant reengineering is a good bet.
On the web, the basic DOM API is the most stable. Sacrificing convenience for maintenance these days is what I'm for. Screw the frameworks.