I'm not in any way against Google removing link schemes from the equation. BMR and ALN getting deindexed might be the best thing happening to SEO in years.
But then again, it might also be the worst. A lot of people use these services on great sites that attract visitors with quality content.
As these sites drop in the search engines, they are usually replaced by even worse results, which leads me to question Google's actions, as I always do.
But here's the real problem that might just kill SEO...
Given the new rules on unnatural link building that Google has introduced, you can destroy a competitor's website without even owning it or getting access to it.
I have read in countless forums about this sort of thing occurring. The message shows up in GWT that unnatural links have been detected. A few weeks later, the site gets hit with a huge penalty.
If Google continues in the direction they are going right now, two things will happen, neither of which will benefit the searcher or the SEO, or even Google:
1. SERPs will look chaotic. Due to the difficult of generating rankings, it will be almost impossible for anyone to control, so the front page will go from a refined competition with relevant businesses trying to rank to a complete hodge podge of random crap with no consistency.
2. SEO will die, at least on Google. The rise of negative SEO will make it so impractical and risky to rank that very few people will bother with the risk.
Why bother ranking when a competitor can waltz in, spend 50-100 dollars on Fiverr blasts, and watch as your site tanks a week or two later?
I'm not saying this is for sure the death of SEO and the decline of Google. I'm just saying, why bother taking even just one step in a bad direction.
Google should be a lot more careful than this with penalties.