This is a very good point. All the JS frameworks I know of solve a real problem. Still most of them are just horrible unless you know exactly how to use them properly. Then again, UI programming tends to be ugly in any case (at least when you're stupid and do all the wrong things).
WRT jQuery, I'd even go further and say there's nothing wrong with jQuery perse [0]. It's just very hard to write modular, easy-to-read, reusable code with it. If you're smart enough and can come up with a good architecture, or if you need just a dozen of lines of JS, jQuery (or a lightweight reproduction of the API, eg. Zepto) might be the best choice.
So yeah, work on fundamental programming skills; learn to design good software architecture; and stay critical. You can work with most technologies, and you can mess up with all of them.
WRT jQuery, I'd even go further and say there's nothing wrong with jQuery perse [0]. It's just very hard to write modular, easy-to-read, reusable code with it. If you're smart enough and can come up with a good architecture, or if you need just a dozen of lines of JS, jQuery (or a lightweight reproduction of the API, eg. Zepto) might be the best choice.
So yeah, work on fundamental programming skills; learn to design good software architecture; and stay critical. You can work with most technologies, and you can mess up with all of them.
[0] I'm a Finn btw