Re: No it isn't. Not defamatory at all.
> Reality is, a sinecure has meant money for nothing for hundreds of years.
And?... Your point is?
A term meaning "money for nothing" definitely doesn't strike me as a sure-fire evidence of overflowing antisemitism. Oh, do you remember that well-known Dire Straits antisemitic anthem (they even added "girls for free")?...
IMHO your trigger is set to so sensitive you're bound to shoot yourself in the foot regularly.