Anything that is creatively mine should be attributed to me. There are some things that aren't creative and other things that are. If I'm creating something new, either totally new or synthesizing multiple sources together to create something new and expending effort to do so, I should be given attribution for that effort.
I think that Jeff said it best in the 2010 blog post titled "Defending Attribution Required":
The whole point of Stack Overflow, Server Fault, Super User, and every other Stack Exchange site is to give credit directly to the talented people providing all these fantastic answers.
The CC BY-SA 3.0 license defines "appropriate credit" as in the informational dialog (click on "appropriate credit"):
If supplied, you must provide the name of the creator and attribution parties, a copyright notice, a license notice, a disclaimer notice, and a link to the material. CC licenses prior to Version 4.0 also require you to provide the title of the material if supplied, and may have other slight differences.
There are some things I'm willing to let go, such as including the full license text. I'd be OK with naming the license (and version) instead of including license text, especially if it's a widespread license. But otherwise, I do agree that property attribution includes the name of the author, the name of the license used, and a link to the material.
I also believe that this credit should be visible in both open-source and closed-source software distributions. In an open-source application, perhaps in-line comments with attribution is sufficient. But if people don't have access to the source, there is effectively no attribution. The attribution needs to exist when people download the source or download an installer or binary files.
I think there's another side, too. Why do you use Stack Exchange?
I primarily use Stack Exchange for professional development - Stack Overflow, Programmers, Project Management, The Workplace, Software Quality Assurance & Testing. When I'm answering these questions, I'm not only helping people, but I'm building a professional reputation. If people take things that I've spent energy to create and don't attribute it to me, it's harder for me to build professional reputation and a solid demonstration of my knowledge base. For me, having more incoming pointers to my posts on Stack Exchange sites is important.
But not everyone sees it that way. For example, I don't necessarily care about my posts on Photography or SciFi & Fantasy or Gaming. These are hobbies to me and I'm not trying to build a reputation. I'm just trying to be helpful. There may be hobbyist software developers contributing on Stack Overflow, Programmers, or Programming Puzzles & Code Golf who don't care about attribution.
I'm wondering if there's a correlation between why you use SE and what attribution you expect from your contributions.