Socialists and taxation

People often say it is immoral for Governments to tax people. If people want their money to fund a health service, or to alleviate peoples' poverty etc, then it should be voluntary. So, in the context of funding a health service, someone on facebook said:

"Forcing others to do things, even righteous things, is not morally sound. That is also basic common sense".

But this is confused thinking, perhaps deliberately so. Think of a rich person who is a socialist. He thinks society ought to be a great deal less unequal than it is. He personally could give most of his money away, and for no other rich person to do so. But that won't make much of a dent in alleviating peoples' poverty. All that happens is that he becomes that much poorer, but without really helping anyone else since his wealth spread over millions of impoverished people will not make much difference to any of their lives.

What he wants is for all rich people to give a large percentage of their wealth away, not just him alone since the latter is fairly futile.

Now suppose all rich people felt the same way. In that case the Government is forcing them to do what they want as a collective whole. But, in this sense of "forced", it would be ludicrous to suggest the Government is acting immorally. Indeed, it's quite the converse, the Government would be doing the right moral thing.