Legal Question in Business Law in California

Probably. The bigger question is whether it's worth fighting. It sounds like the provision wasn't expressly waived, was in bold language and the agreement was signed.

Any reason you don't want to go to arbitration?

Real estate sale contract arbitration clauses are covered by Code of Civil Procedure section 1298, and courts have held that subdivision (c) thereof requires that the arbitration provision must be initialed by the party before it can be dragged unwillingly into arbitration. CCP 1298 does not specifically encompass most leases. However, CCP 1298 does cross-refer to the definition of "sale" in Civil Code section 1086(b), which says the term "sale" includes a lease or an exchange. So, I'd say 1298 applies and the clause must be initialed to make arbitration enforceable against a party. However, as the prior answer suggests, is there a good reason to prefer an jury trial to arbitration? If there is an initialed attorney fee clause, consider the cost of this to a losing party and the high fees a lawyer may earn for doing a jury trial.