Thank you for posting this. Someone made a good point at the link - there was plenty of Je suis Charlie for slaughtered French cartoonists. Where is the comparable support for French Jews who were slaughtered because they are Jewish - I think it would be “Je suis Juif”?
I suspect it has to do with the difficulty of (legally) bearing arms in private self defense in France.
If this was the USA you can bet that just about every Christian Tea Partier for hundreds of miles would be standing armed around that synagogue just daring Islamists to start something. And would be saying God bless these Jews, even as their theology as yet does not acknowledge Christ.