I'll presume the Vietnam picture is just added to exaggerate the reproach of Americans indulging in barbarism and to let people know it's a worldwide trend, not just a Muslim claim so that the resent is even more valid. In reality, the average Muslim who shouts "Death to America" on the street has little knowledge and absolutely no interest in the culture or history of non-Muslim countries like Vietnam or Native Americans. The smarter ones just use the Vietnam war and other past conflicts in their columns and articles as a pretext to bash Americans or inflame more anti-American sentiments. There is rarely genuine interest or profound knowledge beyond the brief statements of the mentioned atrocities, these memes just serve as opportunistic tools to lash out against the Americans.
That said, one propaganda picture cannot possibly give a good explanation why so many Muslims deeply hate America.
Many in the Arab world would blame the hatred on the complacency of American politics. Support to Israel, wars in the Middle East and all that. I think the way that many Muslims view the world is a more contributing factor than dirty politics. There is a more profound reason for this rage, that cannot be merely explained by American meddling in the Middle East.
A religious component that is often understated. A lot of Muslims considers themselves to be agents of the best faith, so how are they always be the ones that are so underdeveloped, poor and weak, how are they the ones who fall behind in everything? Even though they adhere the most superior religion?
Many radical Muslims see the West as an important factor in the decline of their own society. Hence they call America the great Satan - it is the Satan who tempts them and leads them astray from the right path, which is the reason why Muslim countries are so regressive according to them.
America as a symbol of power is a wonderful lightning rod for the mismanagement of the regimes and peoples in the Muslim world. Rather than to take responsibility for their dire conditions, it is easy to blame the outsider. Scapegoating the infidel non-Muslims. Closing the ranks, so that all negative energy can be directed outwards.
Even 'enlightened' and 'moderate' media outlets from the Muslim world like Al-Jazeera participate in this deceptive front. More than half of their opinion section is filled with one-side anti-American, anti-European and anti-Israel rants and diatribes. So what can you expect from the command man?