I don't think ''big'' is necessarily the problem,I believe ''shape'' is the biggest obstacle for most listening rooms.We'll have to leave the planars and e-stats out of this equation though,as their shape is dictated by design constraints.
Have you ever noticed that most speakers of the vintage variety (especially those of the full-bottom,concert level persuasion) are really kinda wide and deep? I don't know how big rooms were in that era,but man,you needed some serious real estate to fit most of those puppies in.
Now,if you compare (for the most part) modern speaker shapes,most are of the tall,narrow-across-the-front format,although some can get fairly deep.These are much easier to accommodate,and tucking them away unobtrusively is possible even in smaller listening rooms. Up goes the WAF,for those who are affected by such things
When I was young,I went through my period of old-school speaker silliness. Altec A7's, JBL 4560's with EV horns,Realistic Mach One's.I once even auditioned a pair of Electro-Voice Eliminator 1's for about a week before I came to my senses
Now,I have completely abandoned any interest in the old big-cabinet jobs,and am quite content with the modern tall-skinnies.I find that while they are not as efficient,they can do better and deeper bass and easily meet or exceed the output capabilities of the the refrigerators of yesterday.