"Because there are too many Taiwanese studying in the United States." Furthermore, Britain doesn't have much nightlife outside of pubs, and she doesn't have much interest in drinking anyway. Without distractions, she'll be able to bear down and get her master's in a year. The choice exactly suits her requirements.
「因為去美國的台灣學生太多了」，而她要去的英國是晚上除了上酒館小酌、什麼娛樂都沒有的環境，對喝酒沒多大興趣的她來說，這樣刻苦的生活，努力一年就可以念完碩士學位，正符合她的需求。