They could be playing the long view and realizing how much that address space is worth. If I were in charge of IT at those companies, I'd renumber out of the block and start thinking about selling the space, once it gets tight.
I've noticed that the perceived view in the netops community -- backed up by mailing list messages today, even -- is that such an IPv4 broker market is an inevitability no matter what the RIRs do. There are policies about it, but some regions (i.e., APNIC) have a model that encourages reselling space without their involvement.
Many people don't realize how non-trivial renumbering a network is. I transitioned the resnet at a public university from a /19 to a new /18, and it took several months of planning to pull off.
90% of the space was assigned via DHCP, but that remaining 10% which was statically assigned was a lot of work. Imagine tracking down every device assigned an IP address, scattered across a college campus.
Our routing configuration was trivial (single super-net, single site, &c), compacting an enterprise /8 would be an insane amount of work.
The long view isn't making a quick buck off v4, it's moving to v6 as quickly as possible.
I've noticed that the perceived view in the netops community -- backed up by mailing list messages today, even -- is that such an IPv4 broker market is an inevitability no matter what the RIRs do. There are policies about it, but some regions (i.e., APNIC) have a model that encourages reselling space without their involvement.