Re: How did the Posting format come about?
Maybe people just like a bit of color.
I usually colorize my speech, or italicize it, while still using punctuation as appropriate. Sometimes I use italics and color. There are times when a post of mine might include two, three, or four characters, and one's speech might be italicized, while another uses blue text and still another uses green italicized text. A favorite color for NPC speech is brown. I don't use bold other than to indicate emphasis, because I like reserving it for that emphasis.
Why just the speech? Why not? I like a bit of standardization and pattern, and I like the look of just 'so' much color. I use more descriptive text than speech, so to me it looks better to use my color in speech.
I'm not lazy, and I write pretty well, thank you very much, both in regards to grammar and creativity. I find it funny to see 'lazy' listed as a possible reason for using color, when it actually takes more effort. Maybe all the people who use black and white are the lazy ones, because they can't be bothered remembering which color they've used consistently or take the extra steps. :P
You know, over the years, I've developed my own style of handwriting. I make my capital 'S' even in cursive writing to look like the printed version. Is it because I am too lazy to make the cursive S? Because I don't understand that a bunch of people over the years decided that the proper format to make a cursive S is 'this'? Am I juvenile or mentally deficient because I choose to write in this manner? There are letters that I also make more 'printed' than standard cursive, not because I don't know how, but because it 'flows' better for me, and there's probably a hint of individuality in there as well.
And, ya know, pencils have been perfectly good for writing for decade upon decade, and I can't stand writing with them. If I'm writing (as opposed to typing) I use a pen. I'd hunt the office and the house over if I could only find a pencil before I'd give up and use said pencil. Oh, and I tend to prefer blue ink over black, red, and even purple ... which is weird, because I love purple.
And I prefer white paper as opposed to yellow, even when I use paper pads -- even enough that I'll still buy the white notepads if the yellow ones are on sale.
Bottom line, people like different things. Sometimes it's just that simple and that complex.