I know of at least two journals that I publish in that have page limits on the length of papers. I am completely puzzled by this. A journal paper should be as long as it needs to be to derive and explain the results the author intends to convey, since the paper should be the final record on that piece of research. Some papers might need 20 pages; others might be too long even at 10. A hard rule of say 12 pages maximum just doesn't make sense.
I can imagine two reasons for instituting page limits on journal papers: paper costs, and reviewer time. Neither seems particularly compelling to me. Are there other reasons I'm missing? (Notice that both of these are more compelling in the case of conferences, where I would agree page limits make more sense. And even in that setting, papers costs is rapidly disappearing as a reason, and at some point, the question of page limits should probably be reconsidered.)
I do admit that there are many papers where the author should be forced to edit things down further, and most authors have a tendency to write too much rather than too little. But it seems the right answer to this is to have good reviewers and a good editor firmly tell an author that the paper is not yet ready and needs further editing. A page limit doesn't adequately solve this problem and raises new, more unpleasant ones.
Anyone want to defend this practice? Or at least suggest reasons for it I haven't thought of?