is why

xyu201

She won't go to the mall because she hates crowds.

If for some reason I wanted to paraphrase this sentence using an \"is
why\" construction, I suppose I might say

(1) She hates crowds; this is why she won't go to the mall.

or

(2) She hates crowds, and that is why she won't go to the mall.

or maybe even

(3) She hates crowds, which is why she won't go to the mall.

But while I might use a demonstrative pronoun (\"this\" or \"that\") or
relative pronoun (\"which\") as the subject of \"was\", I can't see using
any ordinary sort of noun phrase in that slot. All of the following
strike me as intolerably awkward if not ungrammatical:

(4) That she hates crowds is why she won't go to the mall.
(5) Hating crowds is why she won't go to the mall.
(6) Her hatred of crowds is why she won't go to the mall.

Is it acceptable to use anything other than \"this\", \"that\", or \"which\"
as subject of an \"is why\" construction?