People can and do argue in favor of one way over the other via aesthetics, but if you're looking for a point, there is none. Mathematical notation has grown in fits and spurts based on authors and fashions of the times. Some innovations catch on; others languish and are forgotten.
I hypothesize, along with David Mitra and Robert Israel, that a mathematical author introduced it in a paper one day, and it caught on with other mathematicians because it saved them a symbol. While we can argue over the causes, it is the way it is by an accident of history.
According to Doctor Peterson of The Math Forum, using juxtaposition to denote multiplication arises out of the spoken form of saying $2x$ as "two-ex".
Jeff Miller says that this can be found as early as the 15th century in Europe, and as early as the 10th century in India. The cross $\times$, dot $\cdot$ and asterisk * are first attested in the 17th century.
You can read more about the history of mathematical notation at Wikipedia and from
See also the related question about ambiguity of the juxtaposition by multiplication in conventional notation, here.