The purpose of Stack Exchange sites is being a repository of expertise, and knowledge, not a repository of links.
The problem with those questions asking for links to resources is that:
- The resource could not be always available, or stop to be available. If that happens, the answer should be edited, but without any context is not possible to know what the new link to the resource is.
- There can be new resources available. It means somebody would need to add a new answer every time a new resource is available.
- Old resources are probably not so interesting for future users, who just need links to the new resources. The point of Stack Exchange site is not just being useful to who asked the question, but also to future readers. In fact, if the question is only relevant for the user, the question could be closed as too localized.
- Every answer is equally valid.
The link rot problem is also present for those answers that reference an official documentation. It already happened that links before valid have been not anymore useful because the resource has been moved to another link, without thinking of compatibility with the past links.
The difference is that in such cases there is a context (e.g. the programming language, the function name), and it is possible to find the new link. The other difference is that such answers use the link as reference, but the answer is still readable even if link rotten happens. It is different from getting a link to a page that is anymore accessible.
Most of the times, a question asking for resources can be changed in a question asking how to do something; if the question is being asked because a real problem you are having, that is always possible. For example, instead of asking for links showing examples on how to use hook_node_load(), you could ask how to use
hook_node_load() to achieve a task, and if there are other methods to achieve the same result.
If you are writing code, your final goal is writing code, not finding a link. Your problem is not finding a link you don't find, but writing code you are not able to write, or writing code that is more correct when you cannot think of the correct way to write the code.