I amsterdam is a complete branding exercise and not just a sign. It predates the Toronto sign by 11 years and isn't only the city name, it's "I amsterdam".
I don't know what "other" cities you're talking about. There's Hollywood and I suppose there's Hamilton, Ottawa and the soon to be tourist deluged Orono!
And there's no dearth of attractions in Amsterdam. If you purchase an I amsterdam tourist card (60-115 euro depending on duration) you get free entrance to over 70 museums and attractions plus unlimited transit.
On the other hand, if you purchase a Toronto City Pass (from what is actually an American coupon company) for $105 you get free entrance to 5 attractions and no transit. And one of those 'attractions' is Casa Loma so.. 4 attractions. But you can either/or the Science Centre and zoo so.. 4/5 possible attractions..
Dearth
And btw, they removed the sign last year as it was attracting too many braindead selfie zombies, few of whom presumably knew or cared that the exquisite Rijksmuseum was located in the building behind the sign.