It’s interesting you should say that, MDM. My inclination, when this blew up, was to say that ‘Jewish’ is substantially defined, in common usage, by reference to ancestry, and that any really large group - say any that is millions strong - so defined is commonly, usually without offence, called a race. To claim exclusive rights for a race, in this sense of ‘race’, is therefore, again by common usage, racism, contrary to the ‘example’ pushed in our faces by the anti-Corbyn crowd. (Someone might claim, I suppose, that in exceptional circumstances there are justified forms of racism, but we could deal with that claim if necessary.)
Yet I very much see the sense of approaching the question your way. There is enormous commonality and all but trivial difference in the biological constitution of Jews and non-Jews. Perhaps we should avoid terms in common use which appear to have a scientific use but don’t really.