Yes, for the most part, that’s true - the seller is not required or obligated unless they contractually agree to it.
The standard CA Association of Realtors purchase agreement will list this as a contingency for the seller to accept. In the case of REO or short-sale, the seller will remove this provision and make it the responsibility of the buyer.
Here’s the rub;
The buyer of a property is forbidden to do any modifications/alterations to the property prior to transfer - this includes destructive testing, which is generally required during a wdi/pest inspection - without the written consent of the current owner.
On top of that, many lenders will refuse to fund without a “termite clearance,” which is why the provision made it to the purchase contract to begin with.
It’s a “catch 22” for the buyer if they accept responsibility for the termite clearance. Any destructive testing must be repaired to “original condition” (if the transaction is not completed for any reason) at the buyers expense.
If significant damage is discovered, no contractor will touch it without repairing the wdo damage.
There is the potential for a buyer to lose a substantial amount of money if they accept the responsibility for a termite clearance. The risk is too great. That is why it generally falls onto the seller.