Keywords are punctuation for programs. Keywords in capitals are shouting the punctuation out instead of the words. So just as you say, keywords in capitals are

Keywords are punctuation for programs. Keywords in capitals are shouting the punctuation out instead of the words. So just as you say, keywords in capitals are the equivalent of you writing: I think making the keywords all DASH caps is a mistake PERIOD Capital letters draw the eye EMDASH all DASH caps doubly so COMMA and at the expense of readability PERIOD