Personally, I think there are better ways to earn a return on the market without forcing others pay for my investment decisions. I choose not to invest in government debt and would encourage others to do the same.
Writing in 1870, Lysander Spooner was less kind about people who choose to profit by investing in government debt:
"Who, then, created these debts, in the name of "the United States"? Why, at most, only a few persons, calling themselves "members of Congress," etc., who pretended to represent "the people of the United States," but who really represented only a secret band of robbers and murderers, who wanted money to carry on the robberies and murders in which they were then engaged; and who intended to extort from the future people of the United States, by robbery and threats of murder (and real murder, if that should prove necessary), the means to pay these debts.....They lend money to be expended in robbing, enslaving, and murdering their fellow men, solely because, on the whole, such loans pay better than any others. .... This business of lending blood-money is one of the most thoroughly sordid, cold-blooded, and criminal that was ever carried on, to any considerable extent, amongst human beings. It is like lending money to slave traders, or to common robbers and pirates, to be repaid out of their plunder. And the men who loan money to governments, so called, for the purpose of enabling the latter to rob, enslave, and murder their people, are among the greatest villains that the world has ever seen. And they as much deserve to be hunted and killed (if they cannot otherwise be got rid of) as any slave traders, robbers, or pirates that ever lived." - Lysander Spooner
Learn more about the economics and ethics of government debt and taxation in the Freedom Unfiltered Liberty Library.