The advantage is that it's cost effective, and the cost will probably be born by the employer. Also the opportunity to attract and screen top talent would be beneficial to the industry in the long run...they might be willing to start at $30K, but winners will insist on a good wage before too long.

The downside is that US 121 pilots have to operate in a GA-intensive environment, especially domestic ops. This is not a factor in the rest of the world...as long as low-time SIC's and IRO's understand 121 ops they are good to go. But here in the US there is a lot more going on than a long cruise flight terminating in a straight-in ILS...listening to the bug smashers on the radio and understanding what they are doing (and what they are about to screw up) has always helped me maintain enough SA to proactively avoid problems.