Whoa there! Once again we appear to differ on how to operate. I suppose it all depends on what you mean by 'contaminated'? If we are talking ice then it may well be reversers are the only thing that will stop you. If you cannot achieve a landing without them you should perhaps not be planning to land there at all. Up to 35% more distance can be required without reverse use on ice.
Not sure exactly what a 'baulked landing' is in connection with reverse use? Are you talking about something entering the runway after you have landed? In which case, EVERY landing on which you deploy reversers is at risk. By your argument one should perhaps NEVER deploy reversers? I assume when you say "why they didn't excessive this option is a big question here." you actually mean the option to g/a before reverser deployment? As above, ONCE they are out it is an absolute last-ditch 'do it or we die' option not to be taken likely, and 'forbidden' by most manufactures and operators.
This from the CAA advice on 'Contaminated runways' (my highlighting)
Contaminated runway operations remain the exception rather than the norm in the UK, therefore additional guidance is required in order to establish an equivalent level of safety. A stabilised approach is recommended using the maximum landing flap selection in order to minimise landing speed and landing distance. Research suggests that in airline operations the speed at the threshold is on average 5 kt to 7 kt above the scheduled value. This equates to a 10% increase in stopping distance or a 5% increase in the overall landing distance. Airbus currently quote an 8% increase in ALD for an additional 5 kt approach speed. Floating above the runway before touchdown must be avoided as it may use a large portion of the available runway. The timely application of all retardation devices (speed brake, brakes and reverse thrust) should be applied after touchdown.
It is really very simple. Apply the dispatch planning requirements. Ensure your 'in flight' landing performance remains adequate for the situation. Approach at the correct speed with the correct flap and land in the correct place, deploying ALL stopping systems on touchdown. If something gets in the way of all that, perhaps have another go to get it right or go somewhere else.