Hmmm, some interesting statements. I am finishing a walnut every day table now with poly & I think it looks ok. I agree that shellac looks better but for a heavily used table poly, to me, holds up better than shellac. I don't have a spray booth so I have to brush on whatever I use. For a decent size table, 40"X60", it is hard to get shellac on before it starts drying which result in overlap marks. If you can do it I congratulate you but I cannot. You have to work very fast & I am not that good.
Also, I rub out poly all the time. I don't find that it is "soft", in fact, it is a bit hard to rub out. I use rubbing and polishing compound usually to get out the dust nibs and uneven places and it comes out very smooth and looks good. If you are good enough to end up with a smooth poly finish without some rubbing out then you are way better finisher than me and have a way cleaner shop. Unlike shellac, I have to be careful not to rub through the top layer. I never use satin to get a satin finish. Rubbing out gloss will leave a satin like finish.