Linkbuilding is dead as a whitehat practice, therefor, whenever so called SEO experts even mention linkbuilding, we should be very cautious about accepting their advice.
In the past, SEO's and webmasters would submit their pages to places like DMOZ - the Open Directory Project, and other lesser recognized directories. The fact is, however, that no directory truly provides enough value for users when compared to modern search engines. People don't use directories – or at least seldom cares to use them. Search engines often return a larger, and unfiltered result, than what is available at places like DMOZ.
While directories was once a good way to get legitimate whitehat links, it has increasingly become of less value, especially so as search algorithms has improved further. The idea about having a human edited directory is dead, since automated algorithms can be just as adequate as humans, for determining the quality of different pages – and they do so without the delay of manually maintained lists and directories.
Linkbuilding is harmful to the web
The practice of linkbuilding is harmful to websites that do not practice linkbuilding as part of their SEO, as such, linkbuilding should be considered a blackhat technique.
Not only is linkbuilding harmful to competitors, it is also very spammy in nature. This is most often the case, when for example, it involves posting comments on blogs, asking for links, posting on forums, or even buying the links.
Search engines are actively fighting spammy links, sometimes penalizing the websites these links point to, making it increasingly difficult to build links that have the desired effect.
What are whitehat alternatives to linkbuilding?
When we want to promote our websites without using blackhat methods, we do not have many options, other than focusing on our on-page SEO, which would include quality of content and improving the user experience of our websites.
This might seem boring to someone who is used to doing a lot of SEO, but once you have a website with a fairly big audience, it actually is not that bad. Everything, almost, seems to be driven by the raw quality that you provide, and here it helps to create unique content.
While guest blogging can be of some use, if you consider yourself an authority on a subject, it has generally become very spammy in nature sometimes even completely automated – and then there's always the question: "Why not just post the article on your own website?"
If you do guest blogging, then it is perhaps therefor best, to only write for larger recognized sites.
Finally, we also have the option of advertising, though this can be costly for smaller personal sites. But there you have it, why you shouldn't build links!