I've seen this for nearly all long distance flights I try to book. My take:

If my employer is paying for it, and they are too stubborn or foolish to take advantage of cheaper round trip tickets, they deserve to lose money. I'm not paying for it, so I don't care how much more the 1 way ticket is.

If I'm paying for it, I'll just buy the cheaper round trip ticket and then "forget" to show up to the airport for the return journey.