People aren't "out of nowhere" gluing these together. Omitting the operator generally means that you should consider the multiplied numbers as one term. Let's change what's in the parentheses to simply "x". The problem now is 6 / 2x. Many people looking at this expression will consider 2x as one term. So they will read it as 6 / (2x), not (6/2)*x. That's the main reason why some people are in the 1-camp. No operator implies the multiplication already happened and should be taken as such as one term. Frankly it's a poorly written expression, as explained in the article.