Sometimes companies do buy offices. But very often they don't, either because they don't want to or can't afford to. Sometimes they buy offices, then rent out space to other companies. Sometimes they sign long term leases, but then change their plans and sublease to others. It's not at all clear to me what people are arguing for here. Companies rent office space because they've judged it the best use of their resources. They aren't being victimized by some landlord class, they're making resource allocation choices.