That's true - but airlines within the bmi group have the first round of de-icing decided by bmi OPS on receipt of the Met Office weather/icing forecast the night before; therefore, on slot 1 flights, the Captain can only decide to request another de-icing procedure, in case of heavy snowfall/freezing precipitation, ATC slot or tech delay.
The handling agent does NOT decide whether or not to de-ice; it's actually one of the first questions the dispatchers ASK the flight crew during a turnaround.
Incidentally, de-icing is NEVER a rip-off; would you prefer to take-off in icing conditions without de-icing? Remember that different aircraft might have different de-icing/anti-icing systems, the operating airlines might use a different set of weather parameters to define icing conditions, etc.
The CAA has a very good mantra on the subject: "if in doubt, don't think twice, de-ice".
Cheers
