It's not as simple as that.
First, on the issue of money printing being the direct and ONLY CAUSE OF INFLATION, it's worth pointing out that prior to John Maynard Keynes, inflation WAS the printing of money - as in, that was its definition. Keynes and his followers didn't much care for that because their goal was to inflate the money supply as rapidly as possible while minimizing price inflation EXPECTATIONS. Money printing is easily measured, so if people connected the dots between money printing and price pain, they would likely force the government to stop printing. Not good for the Keynesians.
So they launched a largely successful campaign to change the definition of "inflation" to something impossible to measure - the system-wide increase in prices. The disassociation allowed politicians and central bankers to print like crazy while still reporting low inflation. Control words and you control men.
Still, if you look in a reputable dictionary, you'll see that at least one of the definitions is "an increase in the money supply."
Changing the definition was part of a game to keep the public ignorant of the implications of their actions. I'd say it worked.
Second, money printing is NOT the direct and ONLY CAUSE OF [systemic price] INFLATION. Systemic prices are a function of both money supply and production. Prices rise when money printing outpaces productivity gains. If the two grow in tandem, prices stay the same.
Think of it like this. Money is a commodity just like any other. Prices rise when the supply of money increases faster than available goods people wish to buy. That could happen because of the printing of additional money, but it could also happen because of a decrease in available goods.
Third, while Nixon took us off of the gold standard, he had no real choice.
FDR had made it illegal some 40 years earlier for Americans to redeem dollars for gold, and the combination of the Great Depression, World War II and devastated world manufacturing ensured that nobody else was in a position to redeem many dollars for gold either. That freed the U.S. up to print vastly more dollars than it had the backing for, a privilege it took extraordinary advantage of between 1935 and 1965.
By the late 1950s, Europe's economy was recovering. France, in particular, was highly productive and had warehoused a sizeable stash of dollars. They quickly figured out that at $36 per ounce, the United States couldn't possibly have enough gold to back all the dollars it had printed. In short, dollars were overpriced and gold was a screaming deal.
During the Johnson years, France started redeeming dollars for gold. Johnson stepped down as President in 1969 and Nixon took over. He realized that he was the sucker who was going to be in office when the United States ran completely out of gold. By that time, there was no way to reverse course. Too many dollars existed, there wasn't anywhere enough gold, and it was clear that France was intent on taking ALL of America's supply if he didn't stop them.
So that's why he did what he did. I don't think it's what he wanted to do, but he'd inherited an untenable situation from Woodrow Wilson, FDR and nearly all of his 20th century predecessors.
I hate fiat money. But can you blame Nixon for refusing to turn over the nations' entire gold supply to France? What would that have done to the country? We'd still have had tons of dollars floating around, clearly backed by NOTHING, and not even backed by a government that naive idiots thought until then warranted their trust.
So I guess I'd have done the same thing. By that time, there was no other choice. Economic collapse now? Or economic collapse in another generation or two? Who could blame him for deciding to push the pain down the road. The cards had already been played and Nixon was the one stuck holding the bag.
Okay, that's a pretty bad mixed metaphor, but I trust you get my point.