I see it being used by skilled native Deaf signers all the time. Language purists will tell you that is because such individuals have been "influenced" by English signing. The purists state this as if it is an infection.
I am not a sociolinguist, but I am somewhat knowledgeable about sociolinguistics. I'm simply going to point out this one fact: "Language changes."
If many members of a community start regularly using a word borrowed from a different language, that word becomes part of the local vocabulary.
So, I'm going to show you the sign.
Three versions of this sign:
BECAUSE: (Version A)
BECAUSE: (Version B)
BECAUSE: (Version C)
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