Very short sighted mentality. It assumes that people are cogs and the measurable effect of working with someone is the amount of tangible output. Working with extremely talented developers can fundamentally change your perspective about how you should be building your system / approaching a problem that can have huge future benefits. I would rather work with a genius for 12 months than a cog for 3 years.
Are you kidding? The notion that people (even talented people) can be swapped in and out every 12 months is a far greater assumption that people are cogs.
From a co-worker perspective, yes, I'd rather work short-term with someone talented. From a managerial perspective, I'd first choose the talented employee who has demonstrated an ability to commit, then I'd choose a less talented (but with potential to improve) employee who I believe has an ability to commit, then it's roughly a tie between someone mediocre and someone talented who will likely abandon their project in the lurch. Those last two are both pretty lame options.
