I don't say that it's *wrong*!
Only that you should take the time and check for yourself. One could actually learn something from doing so...
If the statement above would be something you categorically should do, then you must:
1) Always calibrate with yourself placed in sweet spot.
2) Calibrate whenever a new person enters the calibrated area.
3) Calibrate whenever objects changes or moves in the calibrated area.
I have calibrated a lot of rooms and home cinemas, so this experience is not only based on results in my own room.
But, heck - do as you please.