Earlier quoted context omitted.
No, US-American tourists
As a frequent reader of r/europe, Americans have FAR from the worst reputation for tourists within Europe, it's not even close. At least among larger countries, they might actually have a better than average rep.
Most US-Americans that I have encountered (both abroad and stateside) are a lovely bunch, great tippers, and have a distinct happy-go-lucky attitude that is hard to find anywhere else.
The crux: When a place gets popular with a certain tourist demographic (through Instagram, Tiktok, whatever) there is an inflection point where the place / experience starts to become commodified, expensive, and bad.
Similar to an influx of large amounts VC money in that niche community app that you used to love.