You are correct, Jim; most match collectors only collect matchcovers. They collect all kinds and tend to accumulate them in quantities of 1000's or maybe 10,000's. Their storage problems would be horrendous if they tried to collect full books.

I think most people interested in casino matches though would like to collect their matches as part of a larger 'casino collectibles' collection. Their collections would be smaller and they can put up with some of the complications of storing things that are not necessarily 'flat'. I do experience the difficulty of storing thick matchbooks and the extra space they take up, but feel it's worth it. I also feel that most of the occasions where sulphur match-heads discolor the cardboard are due to storage in damp environments. Once you get them in binder pages, that's less likely to happen as you store them on your bookshelf rather in boxes in the basement.

My advice is to collect the way you like, but if you eventually want to dispose of your collection if will bring more if the older matchbooks are full and complete.