Who said it couldn't?
Did they say they owned a 5005 and had trouble with it themselves?
The machine shouldn't work any differently than any other recorder (VHS or PVR) does with satellite.
Now, maybe some satellite channel might manage to put out a signal that would discourage recording (something akin to macrovision), but other equipment would be affected by that too, so it all balances out.
I have cable, and have had a VERY good experience with my 5005 (tho I did upgrade it with the software LiteOn offered at their site, and then enhanced that with Mr. Wizard's contribution to the community ).
I don't see why satellite would be any different, except that the recorder wouldn't be able to control your satellite tuner. You'd have to set the channels manually. (And that'd be true with a cable box as well.)