I think we are talking about two different ideas here.
Far on the left, there are liberal (no totalitarian government) socialism and communism, which require a very specific kind of population to work. This population must be industrious (no-one sitting on their laurels) and altruistic and there cannot be any "careerists" (those who take advantage of the system for power). Unfortunately, random genetic assortment prevents this from occurring unless we can find a way to code it out permanently. There is also the specter of the USSR, which is totalitarian control of the economy.
On the moderate left there is universal free healthcare for all. Again, it has the same potential for abuse as above, but it isn't socialism because there is a free market for other things like shoes, toothpaste, finance, etc.
In the middle you have social security and Medicare, both of which face under-funding and a spike in use due to an aging population.
On the moderate right you have the "rugged individualist" society in which, like Shuffler said, everyone is industrious, independent, and the government is much like it is today on the inside (the outside will usually be nationalist or pacifist).
The far right splits with either totalitarian control of the economy and exclusively aggressive foreign policy, laissez-faire (very light regulation, save for for things like child labor, elevators, safety systems), or complete deregulation of the economy (no rules at all) and either a night-watchman state or none at all.
We need to decide which we're arguing about. We also need to draw the line between "unfortunate" and "lazy," and what to do with them. Here are my definitions, feel free to correct them:
Unfortunate: Someone who is experiencing negative consequences either beyond their control or that are the results of actions, the consequences of which are amplified by the system.
Lazy: Someone who is not motivated to work for a reason. The definition of lazy cannot be circular- there must always be a reason.
What to do with unfortunate people: help them to succeed by getting them out of their funk with the "public dole". Thus, state-run education, disaster services, low-income healthcare, welfare, food-stamps, etc. However, there must be a review of the person in order to see if the help is working. Drug addiction places someone in the "unfortunate" category because the definition of addiction is that use is beyond the sufferer's control.
What to do with lazy people: see if they are just lazy or indeed unfortunate. Depression, addiction, and other disorders can easily masquerade as laziness. The truly lazy should actually be satisfied with their life and thus not helped if the aid is non-negligible (e.g., if you're just buying some food once in a while, it's not a big deal for the budget, but totally subsidizing people's lives if they aren't producing anything otherwise unattainable in return is unacceptable).
That way you avoid a good deal of suffering, people are happier, and no-one is "stuck". That way being lazy is either its own reward or you can easily get out and compete on a level playing field. That means positive action to get people out of the funk. In the end it saves you money because the economy gains access to more human capital, thus leading to growth. The process must be continuous in that aspect, but many problems are like snarls in fishing line- take the time to undo them and they shouldn't come back, or at least long enough to make undoing them worth the effort.
On drug addiction itself, much of it starts in the teenage years when the brain is prone to weigh reward more than risk. That is not being irrational- the input changed, not the machine. It looks like this:
Reality->Preprocessor->Rational Mind->Action
It has been proven that this "preprocessor" is present in all of us. It's why advertising and propaganda work well; they play on our 'heartstrings' or 'preprocessor' to create choices that are both rational but not based in reality. During adolescence this preprocessor malfunctions and weighs reward more than risk (evolutionary baggage). Thus, doing drugs goes from dangerous to OK and back to dangerous in the space of about 25 years, with around 15 of those years being the OK part. This isn't true for everyone, but it does happen to most. This temporary malfunction can lead to drug use and later drug addiction. However, once addicted the person doesn't want to stay that way. Unfortunately, life as a heroin addict doesn't do wonders to your self-esteem, either. It can sap your motivation and make you depressed, which creates what I call "bum syndrome": apparent laziness caused by hidden but powerful brain and emotional damage.
That's why there will always be "bums on the street". They aren't there because they're happiest there. Most are miserable but too downtrodden to get out of the funk. Fixing them isn't easy, either; it can take years of intensive and expensive therapy to get them off the drugs and feeling good about themselves. The drug use itself can also precede the damage, which makes the problem even worse by requiring the 'bum' to deal with their particular mental disease while going through withdrawal.
The biggest problem, however, is the labeling. No-one wants to help a 'bum' because they are perfectly broken. However, the homeless include disaster victims, the lost (literally), and those with untreated mental diseases. However, a good chunk of people forget all that because it's easier to just lump them all together into one big category of perfectly broken sub-humans who deserve to suffer. You know what doing that should remind them of? Being a bum.
-Penguin