I'm also confused by their own summary: "According to the results, the quicker a cultural item rockets to popularity, the quicker it dies. This pattern occurs because people believe that items that are adopted quickly will become fads, leading them to avoid these items, thus causing these items to die out."
That seems to me to describe the psychology of non-adopters, not peak adopters who drop the service/item quickly.
Yes, and they are also assuming that sudden popularity causes the sudden unpopularity. If the trend they describe is true and common, it might be because the large number of people who follow fads quickly don't stick with them for long, while things of real quality take longer to be accepted, but are worth keeping around. Therefore, the conclusion and advice should be to make a high-quality product.
That seems to me to describe the psychology of non-adopters, not peak adopters who drop the service/item quickly.