I would say without evidence, it's ineffective, but maybe you are planning to provide that evidence. But with that said, it still seems ineffective to me because it's an absolute statement that seems to immediately be arguable even before supplying evidence for it's truth. The claim suggests that "all" Americans do not go to museums. If this were true, then why are there museums in the United States? Someone must be going to them or they would completely shut down. Maybe a better claim would be, "Most Americans do not visit museums," or, "Museum attendance in the US has declined over the past ___ years and this suggests that there no longer seems to be any interest in them." These claims suggest that yes, while some Americans go to museums, the majority do not. To me, claims that are not absolute in nature tend to be easier to swallow. Just my opinion.
