I'm not up on Brentford's history but I think this has something to do with us starting the experiment at what is statistically one of the lowest ebbs in most fans' lifetimes. Patience is thin. Similarly, everyone bought into last year's team only for us to take a sharp left turn. I think a gradual implementation of this plan would have carried more fans along with it.
Matthew Benham at Brentford invested millions onto the playing budget to get them into the championship. They didn't run sustainably like we are trying to - not that I'm against that ambition.
Clem has invested millions too, but almost entirely to clear debt and doesn't have bottomless pockets like other owners to run at a £1m+ loss every year.
Tony Bloom at Brighton invested over £100m to get them where they are now
Both Brentford and Brighton have spent the money wisely and run their clubs well but it wouldn't have succeeded without the initial cash boost. You almost certainly need both and a lot of luck to do what they have done.