I suspect the bulk of these local politicians are completely taken aback by the level of (justifiable) scrutiny they now find themselves under.
You have to remember that local politics typically exists in a tiny vaccum, the councillors themselves often just cosplaying some wet dream of doing it on a national scale and trying to climb a greasy pole - whilst those in the community who fully engage are often simply the members of the public with the most time, money and energy to do so (the venn diagram of which overlaps significantly with 'nimby').
These people are used to, and entirely comfortable with, their low level meetings, hustings, canvassing and general politicking - that for 99% of the time requires them to do very little genuine engagement with their constituents.
It changes with something as significant as this. Inboxes over-flowing, replies on social media, being held accountable for previous comments and any hyprocrisy. This is democracy in action.
You can see from the above LD comments that there is a nervousness and reticence to outwardly opposing the stadium where once there may have been forthright confidence in doing so.
These people are fallible and can be persuaded.
So keep the pressure on, and keep reminding these people that they serve us.