Drink or Inoculation?

I remember as a kid growing up in the 70’s when the older people would get tired or rundown they would go to the local doctor. It was very popular during this era for a doctor to give you a shot of B-6 or B-12. This would boost your energy level for a week or so. During this period in time, most people also consumed a lot of coffee or Coca-Cola that was still made with a derivative of the coca leaf aka cocaine. What has become very popular in the last ten years or so is energy drinks or shots, meaning smaller drinks that are more concentrated. I myself have become very dependent on these and use them on a daily basis. I am constantly receiving opposition from friends and family for doing so. What I do not understand is what the difference in opinion now versus then is? Why is an inoculation acceptable every week and nothing but condemnation for the drink?