No problem with taxes, fees and charges imposed per passenger by third parties. But I consider charging you the 'fuel surcharge' to be criminal. If you follow the airline's logic why aren't you paying a aircraft parking charge supplement, or a cost of your pilot's salary charge, etc. etc.
When I earned those miles on revenue tickets I didn't get extra when I paid my fuel surcharge, so why do I have to pay for fuel when I'm using my miles.
I think one large British Airline was fined by the US DOT for doing so, but I haven't seen that prohibition extend to other origins.