There are quite a few things at play here. Let's start by admitting we're not comparing apples to apples. Alcohol is a widely available mostly non-addictive substance that hundreds of millions of people use on any given day without any real side effects aside from whatever the alcohol does. Obviously drunk driving, fatty liver disease, etc., are health problems caused by alcohol.
Heroin (if we're going to keep on this drug in particular) is currently not widely available, however the effects of the drug are far more severe and it is without a doubt more addictive than alcohol. I find it quite strange that you make the statement that: "alcohol disproportionately affects people around alcoholic through various forms of abuse". First, these are rare occurrences given the amount of alcohol sold and used on a daily bases across the planet. Aside from specific genetic mutations, it's not exactly easy to get addicted to alcohol. Casual drinking =/= addiction. Second, you're not considering how heroin affects those around the addict. People who are addicted to heroin will do nearly anything to get a fix. It's a completely different level compared to alcoholism that I've seen. You don't see a lot of functioning heroin users. There's a reason people are talking about the streets of San Francisco being littered with used needles. Why aren't they talking about the streets being littered with bottles of Jack Daniels? It's certainly worth investigating since if you compare alcohol consumption to heroin consumption, heroin is a rounding error (at the moment).
Finally, your statement that the effects of heroin being more localized to the drug user are... frankly, laughable. Do you think people are just sitting around quietly shooting up and then going about their merry day? Maybe taking a nice bike ride to Golden Gate Park or picking their kids up from school?
I honestly do not believe you have had any experience around any actual hard drugs based on what you're writing here. Obviously experience is just one data point, but when you're saying "Alcohol is a hard drug too" when we're talking about actual hard drugs like heroin or cocaine I have a hard time really trying to figure out what to make of your statement here.