You are of course correct on all counts, Bill. But I love words. They are not simply tools to an efficient end. Ideally, they are to an idea what seasoning is to food. And oftentimes, the forced edits necessary to fit within the character limit, change the flavor and color of an argument to its detriment, and attenuate its esthetic appeal. 

I am perfectly capable of skipping over comments that contain a compendium of proof-texts or circular, shallow arguments. My libertarian instincts make me chaffe against paternalism and one-size-fits-all solutions. But I do want what works best for the AToday website and hypothesized readers who are intimidated or repelled by anything longer than 1,500 characters. I usually find that the comments are more thoughtful and stimulating than the Commentary, which has no such word limit. 

I think your idea is good. Have a "side room" for each posted offering where commenters can go if they wish to exceed the character limit. Oops - no more characters.