Usually short-sighted micro-economic crud.
Seriously, this is the same old bollocks.
"Look, the past was like this, so the future will be Exactly The Same."
No it won't. Every change in society offers unique problems.
The whole "service economy" thing was nonsense in the first place, because information is logistically easier to offshore than manufacturing was, and it didn't even protect jobs for a generation.
Our "service economy" is a big old pyramid scheme that's trying to maintain higher wages here than elsewhere, but as a result, we've devalued Real Work so much that we have to subsidise our farmers to stop them all ending up in call centres and leaving us importing all our food.
Sites like Freelancer could shape the future to some extent though, but only because it increases the number of suppliers, therefore increases the competitive pressure, and if eBay and Amazon Marketplace have taught us one thing, it's that once you start an auction, there's always someone daft enough to take the price a couple of quid too far. Various design and coding "competitions" have also shown that this holds for the job market too -- unemployed people will happily complete a full job for the mere possibility of being paid a distinctly average sum at the end of it.