Here we are at the dawn of the movie era where directors and actors begin to understand and reveal the techniques best suited to the silent screen.
We should not forget that this is 1909 and the requirement to survive in the new and novelty 'industry' at that time was mass production, they were knocking out more than 50 'movies' a year with limited equipment and a small group of regular performers. There was no time to waste, no time to be reflective and do multiple takes and experiments and then choose the best one. A decision was made then the action filmed - another dozen movies were lined up behind what was being done in the moment.
Griffith was the product of his time - his father a Southern military officer during the Civil War and DW of strict moralistic upbringing.
Griffith often visited moralistic themes in his movies and this was the prevalent thinking and attitudes of the time. In his own time nobody would have thought this over moralistic and, we shouldn't forget that 'Prohibition' was the end result of societies concerns over alcohol. This was the era in which lynchings of African Americans still spontaneously occurred, Chinese were called Chinks and it was illegal to cross marry.
Griffith had high visions for film as revealed in 1914 interviews were he saw them as a 'push button' teaching aid in libraries replacing books and encyclopedias. No doubt they could be used for 'moral' purposes as well.
This little film should not be seen just as Griffith going over-board on alcohol but a pointer to community values and concerns of the time.
I believe the subject matter and purpose lent itself to melodramatic acting - it was intended rather than a flaw. The violence and harshness coming from alcohol abuse was deliberate and would have touched a chord with many.
The movie is not as bad as we would like to think in modern times - it should be judged in the context it was produced and the effect it was meant to achieve.