My run of the mill thinkpad has operated at the summit of Mauna Kea (~14,000 ft) many times. I've personally also used a Gateway laptop, and a couple of seagate 2.5" harddrives up there. I know of many people who have used other laptop models there as well, and have never heard of any problems. The pressure difference between 14000 ft and 150000 ft is only about 15%.
I strongly suspect Dell just pulled the 15,000 ft number out of their rear because some marketing person thought it sounded neato.
Until I read your post, I envisioned someone watching a computer screen with thousands of little dots overlaid on a floorplan of the airport, and saying something like: "Congestion at security line 6, open 2 more lines", or something like that.
If there are only a few dozen people using the airport, I don't see how anyone can interperet this as anything except 'big-(Hungarian)-brother'