Oh, interesting. A couple hundred years again, it used to be the done thing in written English to capitalise every noun in a sentence, German-style. The Yanks have “in Order to form a more perfect Union, establish Justice, insure domestic Tranquility”, for example. We’ve mostly stopped doing that now. There were a lot of German immigrants to the early US; whether they’ve taken your influence on colons, or whether it’s just pre-standardisation English and it needed to be one way or another…

We’d consider excessive capitalisation, or worse, running all-caps, to be the sign of a diseased mind, now. Not naming any names.