No, the AC system rewards you by way of AQS or AQM. The WS system as many, and i'm sure you know, is based on spend.

If one can book a Flex fare on WS, one can hit gold even easier. So one is also incentivized to book Flex on WS if possible - in fact, I'd say one is EVEN MORE incentivized to book Flex on WS b/c it's not about miles or segments, it's about pure $$$