The idea behind this was that natural, voluntary, one way links (the best indicators of quality in Google's eyes) will by their nature include wildly varying anchor text, sometimes with seemingly completely unrelated keywords in them. Conversely, much similarity in anchor text implies an attempt at manipulation.
This has left anyone interested in SEO in a bit of a quandary. They know that you should continue to build links to your pages because it still helps them rise in the search engine rankings. But while you do this, you have to consciously avoid making these links look unnatural. It's pretty funny when you think about it.
It's like that famous line that came originally from French writer Jean Giradoux: "The secret of success is sincerity. Once you can fake that you've got it made." Or to put this more specifically: Google doesn't like to be tricked, so now you've got to trick it into thinking you're not trying to trick it ... or something.
The absurdity of this makes you want to throw your hands up in the air in complete exasperation.
And as far as I'm concerned it's all the more reason to just do a lot less link building full stop. Surely the best approach is to use the extra time and energy this allows to focus on putting more really good quality content on your website. That way those links to it will develop and they will be natural.
Sure, you'll have to wait a while to see some results. But the benefits will be more substantial, and last longer (possibly indefinitely) too. Best of all, you won't incur Google's wrath.