[doetoe]

I think this inverts cause and effect: they often were money lenders because they were excluded from more traditional jobs and/or land ownership

[ahartmetz]

It's not inversion, but not going for a root cause far enough. You are of course right. Jews were not allowed to pursue most/all "honorable" professions.

[disgruntledphd2]

It's because Christians and Muslims banned lending money with interest, cf usury.

[Yawrehto]

I thought deicide and a general concept of 'otherness' fueled antisemitic restrictions which in turn fueled antisemitism.

But yes, Jews were often moneylenders because there were no other options available and that niche was conveniently not open to Christians.