I have come to realise that sometimes you can have agreement between lots of different people that a certain course of action will be good, but still it never happens.
Part of this is just down to the question of ownership, who's job is it anyway? ........... A simple example of this is at the church I go to different groups find that chairs have been moved from one room to another and it causes some frustration. Everyone agrees something should be done about it but nobody does anything as they don't personally own the problem (it falls outside their area of responsibility).
I think this can explain a lot of reasons for inaction however when it comes to big issues I suspect the reason for inaction is more down to fear! If you are paid as a senior manager for a company you might know that it makes sense to tackle some internal issues but due to the concern about people's reactions or possible failure you maintain the status quo.
Doing nothing may seem the easiest option as people may get a little frustrated but they won't get into a big conflict with you. Alternatively if you tackle the issue and make changes (even with the right consultation) you may get conflict as although people might agree something needs to be done they often don't agree with how to do it. If the changes don't work then you may come open to criticism and your career profile might be effected. There are a lot of maybes in this but often anxiety and fear makes them seem certainties with the worst possible outcomes. In reality inaction may lead to your fears being fulfilled anyway.
What is truly important is to be principled, do the right thing and act authentically with integrity - Ultimatley this will lead to better outcomes and a more enjoyable life and even if you do suffer some negative consequence you know you did it for the right reasons.
Better outcomes - because everyone knew there was a problem and so in the long term it will make sense to people.
A more enjoyable life - because you have made a difference to the world you live in.