The latter. Their chips aren't sold through distributors, and they'll pretty much only give the time of day to high-volume OEMs. They stonewall companies that are big enough to get in-person visits from sales engineers from other major vendors (TI, Freescale, Xilinx). Raspberry Pi cofounder Eben Upton was a technical director at Broadcom, so he had inside connections.
They normally deal in massive quantities. Asking for a couple thousand units just isn't worth the effort. That's what makes the RPi Foundation unique -- Broadcom _does_ deal in small quantities for them in support of the mission.