Trickerin I'm just as confused as you are.
Just because Google don't like it - doesn't mean it doesn't work.
It's not a tactic I like or use, but for certain hit and run niches it works a treat. Maybe only for 3 months, 6 months, a year or two - whatever. Some sites have lasted years on nothing but gazzilion spam back links.
Don't believe everything you read on WH sites. Really - Don't.
They'd like you to believe that sites with spam back links have all failed and died - nothing could be further from the truth.
It's true to say many have been penalized, and in very high commerciality niches where Google send the manual teams in - they have pretty much been cleared out - but all over the net, in tens of thousands of niches - spam still wins. It's risky - but it wins.
Likewise many site owners who have never created a link in their life have been penalized through no fault of their own. Fact is Google couldn't give a shit - they aren't the internet police.
Google only want to reduce spam as long as reducing spam in their index encourages more people to use it and so they make more profit.
There comes a point where weeding out long tail key-phrases, tight niches and micro niches costs them more than it returns - so guess what - they don't do it. They aren't paid to do, it isn't their job to do it and no-one asked them to do it. No profit = Don't bother. Not because Google are bad - but because they are a "for profit" shareholder lead private company - not some sort of internet police. They don't do it because past a certain point it doesn't pay to do it.
That point? It's some variation of the famous "pareto" rule "80% of the task can be achieved with 20% of the effort/cost. The last 20% of the task takes increasingly more resources to achieve"
That's paraphrasing it before someone jumps up and down on it and says that's not quite right - I know it isn't. But the meaning is the same.
Good BH SEO's know how to hide in the "hard" 20% and are prepared to take the risks involved. The costs are very much lower though - it just requires a more flexible and responsive business mind, but many (frikking loads) of people on this site live in that 20% margin. There is a lot of money to be made there and very few corporate competitors
I'll finish by saying if you are even remotely worried about spamming links to your site and are after a better chance of long terms success (note "a better chance" not "guaranteed" - no such thing as "guaranteed" no matter what you do) then stick to other methods.
Pick the horse to suit the course
Scritty