Excessive or too much of every thing is very bad just as you have said and I also have said a couple of times in my previous posts, but let me point out that people are still different though, there are people who would be under the influence of alcohol and still maintain their stability and normal behavior even when they are intoxicated, but this is still not an excuse to drink excessively..
A very strange observation. People (not all) who have been drinking for a good period, become more resistant to alcohol, have better self control towards drinking. The more they drink the more responsible they are. 21 years old guy who becomes drunk after few cocktails and start to behave inappropriate vs 45 guy who wont get drunk after few cocktails, wont act wild after then; and it will even be unnoticeable that he drank alcohol. One again, not related to all, the longer person drinks alcohol, the more experienced he becomes and alcohol would harm him less.
Now gambling. Whether you are 21 or 45 years old, its still dangerous. The longer you play, the more chances to become addicted are. Young and old gamblers similarly falls of a greed victims. The older gambler gets, the harder for him to stop gambling. With alcohol, the older person gets the better he knows his limits.