[ghaff]

>Run-on sentence are discouraged.

Sort of. This is a somewhat modern thing. There is various punctuation--parentheses, em dashes, and semicolons in particular--that let you construct fairly long and complex sentences. But the modern style, certainly for basic communication, is to mostly break things up with periods. (To the point where it's sometimes OK if the segments are sentence fragments.)

[gpanders]

> This is a somewhat modern thing.

Indeed. Go back and read some speeches from the 19th century (e.g. Abraham Lincoln’s second inaugural speech) and you’ll find run on sentences everywhere. Heck, even the US Constitution is full of them.