The quote you're thinking of comes from the writings of Lord Rawdon, then a teenaged captain in the 63rd foot. Here is the full quote:

The fair nymphs of this isle are in wonderful tribulation, as the fresh meat that our men have got here has made them as riotous as satyrs. A girl cannot step into the bushes to pluck a rose without running the most imminent risk being ravished, and they are so little accustomed to these vigorous methods that they don’t bear them with the proper resignation, and of consequence we have most entertaining courts-martial every day.

So, the quote is true. Was this view widely held by people besides Rawdon? Probably. After all, he was writing to a respected relative. More broadly, contemporary ideas of masculinity celebrated sexual appetite, and having one's enlisted men lean towards the ravenous was a sign of the kind of burly masculinty that could lead them to victory in battle.

Still, it's best not to read this too broadly. We don't really see other people around this period delighting in rape cases like Rawdon does, and such a thing was never policy in the British army. In the article I linked above, historian and ur-reenactor Don Haigst also pointed out an off-overlooked fact: there were no court martials for rape in the British record from this period. As Haigst admits, attacks by British soldiers on American women were likely billed as assaults, both to minimize bad press and to avoid trying soldiers in front of a general (rather than regimental) court martial and sentencing them to death. Keeping the courts martial within the regiment insulated the British senior staff and allowed soldiers to be tried by their own officers, who were more inclined to go easy on them. The fact that the British apparently took steps to keep any attacks that occurred quiet should indicate more general views of them beyond Rawdon's piggishness.

Sources: Don Haigst, "Rawdon's Ruse," Journal of the American Revolution

Thomas A. Foster, Sex and the Eighteenth Century Man