In some areas, our lives are ruled by lawyers. Nothing much wrong with that, as it leads to lower insurance premiums (in nett terms) and an occasionally-ultra-conservative operation.
However, runway state, braking action, contaminants, and so on, all need a good hard look.
In particular, the performance requirements on 'slippery when wet' runways, and the situation regarding braking action reports on snowy runways, are cases in point.
We suffer, in the UK, from having relatively good weather most of the time. When the snow hits, it takes us by surprise, but it's soon gone again. If we had bad snow all the time, we would have resolved these issues.
Maentime, Boeing operators (in particular) will suffer badly if LHR gives 'Slippery when wet', and I, for one, am not sure who will address these issues.....