I have a feeling that a part of the reason why things are as they are may also be a bit like why the US is still using Imperial units, while the rest of the world (even GB - though they still use 'pints' in pubs, probably because it sounds nicer to say to one's mates, 'Let's go down the pub for a pint or seven', whereas 'a half a litre or three and a half' doesn't flow so well) converted to the more logical and connected-to-reality Metric system 50+ years ago. Sorry I can't give you other examples at the minute, as I haven't got any other published collections myself, but I know there are (many) others. In Europe and, as far as I can tell, most of the rest of the world what you might call 'published' chord charts are as in the examples I pointed out to you. As you say, the Realbook and others use a what-one-might-call 'unboxed' layout, mostly, I guess, because they're US books and because if someone is doing it by hand (as it were), it's quicker and easier.
