Eh, I'll have to respectfully disagree with you one that. If it were a dedicated listening position/chair in a professional demo room? I would agree with you 100%, as the typical listening times are relatively shorter than those listening sessions at the house can be. This would also hold true with speakers whose characteristics are hyper-focused in a very narrow, specific sweet spot. Not all systems have this kind of limitation though, some variance of listening position is okay without degradation of the imaging.
While the main reason for choosing the chair I did was for the sound, another important factor for the reason I choose the chair I did was specifically for comfort on longer listening sessions. Some listening sessions (for me) end up with me falling asleep on the listening chair. For those sessions, a non-moveable/fixed chair was a no-no. Comfort comes second to the end result as to what hits these ears but it did remain high on the priority list whilst searching for "the" chair.
While I can certainly have the chair fixed and as a "dedicated" listening chair, I do enjoy (especially on those albums where you want to just relax and enjoy the music, not be critical about listening/evaluating) propping my legs up a tad and listening with a stiff adult drink on my side. Especially when the whole point of your day is to listen to 2 albums of live performances (both of which are double LP's) back to back.
If you do the math on that? That's quite a bit of listening time and for me....this may be just the beginning of the listening session for the day, as I usually will pull out more music to enjoy after that. Being stiff backed in a "proper and immovable" listening position for that amount of time makes me cringe just thinking about it.
So, while I will agree to agree with you (to a point), I will also respectfully disagree with your statement. It depends and priorities can vary.
Tom