By the 1860s, Niagara falls had been covered with hucksters and businesses charging fees for services, legitimate or not, and hassling tourists who came there. It was like a carnival rather than an appreciation of the Falls.
Europeans who visited were taken to chiding the US about such a limitation on grandeur (ironic as it was given their privatization of similar sites).
Alexis de Tocqueville said at the time, "Hasten to Niagara if you wish to see this place in its grandeur. If you delay, your Niagara will have been spoiled for you. In Europe, people talk about the wilds of America, but the Americans themselves never think of them."
He went on to call us insensitive, and say things like we "prefer the useful to the beautiful."
de Tocqueville was not alone in his sentiment. In short, the Niagara Falls tourist trap environment was confirming for many that we were still a bunch of backwards rubes instead of a civilization.
Fortunately, around that same time, the movement to preserve Yosemite happened, transforming into our National Park system, and saving many other places from the same fate.
Unfortunately for nature lovers at Niagara, the Falls today still largely exhibit the same atmosphere of commercialization over appreciation of natural wonder. My family often refers to it as the world's disappointing destination, a play on its self-appointed title of "World's Honeymoon Destination".
EDIT: Editorializing removed per mod request :-)
Source: Several of the museums at the Falls themselves (I live nearby), as well as "The National Parks: America's Best Idea" (Book) by Dayton Duncan and Ken Burns, a companion to the fantastic documentary about our National Park System , which is available on Netflix.
The National Parks: America's Best Idea, a film by Ken Burns
It would be helpful to have some context regarding how the word, "embarrassment" was used. "Embarrassment of riches" means an overabundance of riches, for example.
http://idioms.thefreedictionary.com/an+embarrassment+of+riches