Personally, I picked up a dslr a little over 20 months ago and use it as a relaxing hobby mostly, yet next month i have 3 out of the 4 weekends booked and a few days in between, including a shoot for one of the most famous sporting teams in the uk. There is no way the market is saturated if an 'newbie' can go out and get gigs without advertising. Trumpet blown, but it illustrates the point.
That's true and fair but somewhat misses the point, commercial and contract work isn't what's at risk right now. When companies are getting somebody to come and take specific photos they're going to be paying, small companies are beginning to do the 'my mate down the pub has a D3100 and can take those shots for a few pints' thing but that's at the very low end where, to be honest, there's sod all money anyway.
I shoot fairly niche commercial work and get very decent money for it and I've never advertised at all. It's word of mouth and people seeing my work and asking 'who did you get to do that'. That's great and I enjoy it and I've done some really interesting stuff along the way (seeing next years custom titanium mountain bikes and playing with them for a weekend and getting paid for it isn't a bad gig). That work isn't going to go away anytime soon.
What's at risk is photo journalists, wildlife photographers and people shooting stock and landscapes more than anything. The first two because there's always somebody on the scene with a camera whenever anything interesting happens and they're stupid enough to give away the photos for free so they can go 'my photo was on the bbc'. It's the old Lions on a successful hunt thing - who is more likely to be there to record it? Wildlife photographer or tourist on safari? Today all those tourists have cameras.
The later because there's a far larger pool of photos out there, many taken by people for fun who aren't concerned about the money. Now yes, it's economics at work at the end of the day but it's still stupid because a) they could be making money from their work and b) they're knowingly or unknowingly screwing the people who take the really good shots in the process.
I have no problem with amateurs (by which I mean people with no prexisting ambitions to make money from it) taking the shots, them being used or whatever. If you want to be a professional you need to produce better work, that's a fair argument. But I have a problem with them giving them away for free, and caving to the 'if you charge we aren't interested argument', if nobody gives photos away for free they'll pay, if people do it's a race to the bottom.