可以把這句話簡化下理解，so..as to是以至於的意思，simon is so good as to be popular，simon很善於。。以至於很受歡迎。。as to後邊只是加動詞原形，不是被動語態，is的原形是be。
參考下too..to句型，He is too tired to move。這個to後邊也是加動詞原形。
這句話也可以用so..that..句型表示.simon is so good at making friends so that he is pupular even with plants.
have加動詞過去分詞可以構成被動語態.I have been told by him.我已經被他告知了。