TL;DR PPS incentives the pool to operate at max efficiency, which is good for the miners and good for the network.
Sure there is. By taking on the onus of generating maximum profit for the pool, we are incentivized to make sure the pool is well connected (i.e. no orphans or rejects), make sure that shares are consistently accepted at a high rate and provide services which maximize the pool's efficiency (accelerators, proxies, etc..).
Every share you submit to every pool is detected by the pool you submit it to.