Clients are passengers.
No.
"Clients" originally referred to the relationship between a lawyer and the person he represents. It is commonly used these days where the relationship is very different, often I suspect to imply an unnecessary sense of self importance. Everyone understands being a passenger of the rail company, or airline, or cruise ship - if I say I had enjoyed my experience as a passenger without mentioning "on what" everyone would expect me to have been involved with some form of transport, whereas if I said I enjoyed my experience as a client, they would probably think I had been to see my accountant or lawyer.
Anyway, back to the point.
The relationship between a pilot and his pax can be very different. On this forum we all understand flying with friends. Sometimes they expect us to operate like a mini airliner and cant understand why we might want to stay on the ground when the weather is on the deck, but with luck we can manage these expectations if, for any other reason, they cant fire us!
Passengers, at least in the sense of those who fly on commercial flights, are different again. They have no interaction with the crew and therefore no influence on the conduct of the flight. The pilots' employers may bring other pressures on the crew, but again these are different and managed differently. In fact post 9/11 operators have successfully created a sterile enviroment between flying crew and their passengers.
Finally, there is the relationship between a pilot who is flying his employer which I think is what Pace was discussing. We have already heard of those clients who expect to taxi within minutes of their arriving in the cabin. Where the pax in the back are paying for the aircraft, paying the crew, have immediate access to the crew, and "think they are calling the tune" the relationship is different again. Moreover, in this enviroment, the passenger(s) expect to fly to their time, after all they are paying a great deal of money to do so and it is probably their expereince that this is exactly what they get.
A private pilot on this forum rarely, if ever, has to deal with the demands that can be placed on a commercial crew interacting directly with their emloyer and aircraft owner. Moreover rightly, or wrongly, our regulatory authority demands commercial crew display a different skill set from private pilots.
For all of these reasons clients are not passengers either in sense or substance. Every pilot might have pax or passengers with him, but managing the demands and expectations of those passengers can be very different and it would serve us well to treat each as unique.
That does not mean it isnt an interesting subject for debate, but it does mean you make a fatal error in thinking each is the same as laudable as you might like to treat every passenger with equal "contempt"!