On the contrary, this setup works JUST FINE on the passenger side. In fact better than the driver side (unless you fill in the void on the driver side first - see below - in which case it's the same).I ordered two sets not knowing the passenger seat would not accept the lumbar support.
I think your thought is that there's the void in the back of the cushion on the driver side and that void is not there for the bladder to 'sit in' on the other side. Again, that's void is just a hindrance and gives less for the bladder to push against. I actually filled mine in with a piece of foam sculpted to match the hole