My understanding is that your value to a firm is directly proportional to your ability to generate alpha. Credentials would be useful for securing an entry-level position, but eventually, it is your ability to develop profitable strategies that will secure your position in this industry.
This is such a secretive business, that I doubt academia will be teaching anything other than the fundamentals/theory . As pointed out in the article, MFE employment stats are murky at best. I haven't had much luck getting confident stats. There's only a few of programs that staff actual practitioners, people who, you know, actually made/make money doing this stuff.
One of my concerns with the credential-path is future career growth. Many of the firms that hire from schools place candidates in specific roles that need to be filled. You might get stuck in an area thats not as profitable as other areas of the market. You will also not be exposed to the firm's intellectual property until they've worked you hard and for many years.
Contrast this with the option to start independently. I've spoken with quite a few people who've started out this way. Some have parlayed their experience and performance into jobs/partnerships at the big firms. Others continued to scale and build out their own fund. They all say the same thing, if you can develop profitable strategies, you will find people more than willing to invest in your strategies.
As far as networking, I think the internet is helping that immensely. Quite a few fundamental investors have received job offers or started their own hedge funds from blogging/posting on forums when it became apparent they had an edge. There's always a few headhunters and fund managers hanging around nuclearphynance, and other forums.
There is a higher risk, perhaps, of getting nowhere. But you also have the freedom, and less dogmatic structure to think independently, and the time to learn things thoroughly (vs. in a degree program).
I'd like to hear other's thoughts on this.