If issues are raised with CAA (or BOSE), then the Met Office cannot ignore comments.
Regarding use of the longer range charts for planning booking of aircraft/planning trips, it is a simple fact that the further out you look the less accurate it is going to be, but again actually think about the magnitude of the problem. Even for a front or low that is moving steadily with no changes, if the rate of movement is only 1 KT/hr in error, then in 120 hours the front/low will be incorrectly placed by 120 miles. That says nothing for developing systems that accelerate/decelerate or features that dont even exist on the analysis.
Look where all the lows are on the charts SN referred to. How much surface data is there out there in the Atlantic? Satellite fills in the gaps, but there are many unknowns.
Jetstreams drive the weather, and if they are wrong there will be downstream consequences in days to follow. Airliners crossing the Atlantic report winds but western bound ones will avoid the strongest headwinds (so denying data that would be very useful to fine tune models). Even those heading east and riding the wind may well avoid the strongest winds to avoid the associated turbulence.
There are plenty of other models out there to consult and compare, they will suffer the same issues.
I don't think the MO are out there to deliberately spoil your flying or you barbeques. When I see that many lows floating around to the west over the next few days perhaps the 'hint' is that perhaps conditions will be too changeable to plan anything for certain - paint the front room instead ;-)