Is this blochchain api script ok to use?

[BrannigansLaw]

So here is the script https://github.com/blockchain/receive_payment_php_demo
I know there is nothing sinister about this script, its not going to steal all my bitcoin, as I have basic programming knowledge and have gone through it (all checks out in my book anyway). But in the notes it says "Do not use in production as is." I was just wondering why not? I'm looking to use it and it would work for me but I dont want a work around to be present.

Thank you.