Bridewell made an interesting post about 4 years ago that the word "Juwes" was a nickname for the City of London Police.
"In Paul Harrison's book, 'Jack the Ripper - The Mystery Solved' he claims that contacts within the Metropolitan Police have told him of resentment within the Met at being blamed for everything that was wrong in East London and at being compared unfavourably with the City Force:
"The message was nothing more than a jibe at the City Police. The word 'Juwes' should have been spelt 'Jewes' and was meant to refer to the nickname used by the majority of the Metropolitan Officers when referring to their City opponents. The nickname derives from the Old Jewry police headquarters of the City Police.
If the story is correct, a fact in which I have no reason to doubt, then it explains Superintendent Arnold and Sir Charles Warren's rival actions in removing the message".
That would also explain the superlative use of "the men" in the phrase "the jews are the men than will not be blamed for nothing". If the phrase actually referred to the jews, it would say "The jews will not be blamed for nothing".
By spelling the word "juwes", the writer drew attention to this word. As someone also mentioned before, the hand writing was neat and other words spelt correctly - why mis-spell "jews" unless it was deliberate.