What is the significance of 如き in this conversation?

Question

I'm currently reading the manga "Fruits Basket" volume 5.

Background

The protagonist of the manga is Tohru Honda (本田透). Strange circumstances brought her to live in the same house as her (male) classmate Yuki Sohma (草摩由希). Yuki is a very popular boy, and the school has an unofficial Yuki fan club, consisting of most of the girls in the school. And of course, those girls don't like the apparent closeness between Tohru and Yuki, and pick on Tohru on every occasion. Her best friend Saki Hanajima protects her. The girls in school are afraid of Saki as she has strange powers.

In this chapter, the fan club members decide to try to dig some dirt on Saki Hanajima to stop her from protecting Tohru. They invite themselves to Saki's house on the pretext of interviewing her for the school newspaper. After a while she discovers what they are up to and accuses them directly. The following conversation then ensues, where Saki says "草摩{そうま}由希{ゆき}如{ごと}きのせいで". The fan club girls (Motoko, Minami and Miho) are appalled at her use of the word "如{ごと}き". A bit later when she is left alone she regrets using that word, saying "如{ごと}きだなんて草摩{そうま}由希{ゆき}にも悪{わる}い事{こと}を言{い}ってしまったわね".

Question

What is the significance of of 如き? Why is it so insulting in this context?

Quote

The conversation (a little shortened) goes like this:

モトコ：
　　　おやめなさい。
　　　仕方{しかた}ありません。バレてしまったならば遠回{とおまわ}りな事{こと}はやめましょう。
　　　そうです。私達{わたしたち}は魔女{まじょ}…いえ本田{ほんだ}透{とおる}が非常{ひじょう}に気{き}に食{く}いません。
　　　どうです？貴女{あなた}から言{い}って頂{いただ}けませんか？
　　　由希{ゆき}ともう少{すこ}し距離{きょり}を保{たも}ちなさいと。

サキ：
　　　そんな事{こと}、二人{ふたり}の勝手{かって}でしょう。
　　　嫉妬心{しっとしん}からくる行動{こうどう}は醜{みにく}いだけよ…

ミホ：
　　　嫉妬{しっと}じゃないもん。
　　　頭{あたま}にきてるだけだもん‼︎

ミナミ：
　　　そうよ。何様{なにさま}よあの子{こ}‼︎
　　　由希{ゆき}君{くん}の何{なに}がわかるってのさ。ムカつく‼︎

サキ：
　　　貴女達{あなたたち}こそ透{とおる}君{くん}の何{なに}をわかってるの？
　　　愚弄{ぐろう}される透{とおる}君{くん}が可哀想{かわいそう}だわ。
　　　草摩{そうま}由希{ゆき}如{ごと}きのせいで。

モトコ：
　　　「如{ごと}き」…っ
　　　「如{ごと}き」とか言{い}いやがりますか…っ
　　　聞{き}きました？
　　　聞{き}きましたか、二人共{ふたりとも}‼︎

ミホ＋ミナミ：
　　　聞{き}かせていただいちゃったですとも…っ

サキ：
　　　透{とおる}君{くん}を愚弄{ぐろう}するからよ…

モトコ：
　　　貴女{あなた}こそ由希{ゆき}を…私達{わたしたち}を愚弄{ぐろう}しています。
　　　そのトロンとした目{め}は馬鹿{ばか}にしている目{め}です‼︎

(The conversation continues, but I don't think the rest has any bearing on the 如き issue).

Answer 1

To answer this question, the two usages of 「ごとき」 would need to be explained as they actually are quite different from each other.

1) Neutral 「ごとき」

A (somewhat) literary word that is, in meaning, the equivalent of 「～～ような」,「まるで～～のような」, etc. in modern Japanese.

Examples:

「そのタクシーは[飛]{と}ぶがごときスピードで[去]{さ}っていった。」= "The taxi just whizzed by at a flying speed."

「[人魚]{にんぎょ}のごとき[少女]{しょうじょ}」= "a girl just like a mermaid" or "a mermaid-like girl"

2) Negative 「ごとき」

This is the usage your question is about. The speaker has a negative or pejorative view of a person or thing that he is talking about.

「Person's name (or any noun/pronoun) + ごとき」= "a person/thing (as detestable/unimportant, etc.) as ~~"

「ごとき」, in this usage, can be replaced by 「なんか」 or 「など」. Remember that 「ごとき」 will sound more "dramatic" than the other two, which in turn means that you will not hear us use 「ごとき」 for this meaning in real life as often as you might in fiction.

「草摩由希ごときのせいで」= "because of the little bitch like 草摩由希"

Excuse my French!