I think UI patterns are a good thing because there is only a small number of good solutions to any given UI-problem but an infinite number of ways to screw it up. Identifying and explaining a few proven solutions for the most common tasks can help newcomers to make good choices instead of reinventing the wheel (potentially badly) every time.

I'm really on both sides of the fence here. I said that because I'm currently writing an app that has a completly non-standard design because every app that does what I want uses "search/results" design but it just doesn't work (at least for me).

On the other side, I'm happy to see that maybe a bad UI idea will be standardized into something usable.

Like design patterns, you should learn them so you can both use them intelligently when appropriate, and make fun of people who overuse Singleton or the "Column Browse" template.

Can you overuse a design pattern? You can use them incorrectly or when it's inappropriate, but that's not the same thing.

I think when a pattern is used widely enough, it just fades into the background; when the navigation tools are in their expected places, then the users who have gotten used to the pattern can spend more time paying attention to the content. Which is what we want, right?