It's not an unreasonable approach, if they wanted to migrate passwords they'd have to modify the new system to support the hashing system used by the old system

It's not an unreasonable approach, if they wanted to migrate passwords they'd have to modify the new system to support the hashing system used by the old system. In this case I'm guessing that they've outsourced the process to Taleo's SaaS system so that's not feasible, but even if it would be it may well make sense to take this approach. After all you should avoid modifying a tried-and-tested authentication system whenever possible, you're just asking for security vulnerabilities when you do so. Getting users to go through a password reset process is a relatively painless process.