The club/player culture has been blamed before. Managers come and go. Players come and go. The culture remains.
Honestly, Conte's post Southampton rant about the owners and players was 100% relevant at the time. Was years before he said it and has been years since he did.
With Levy gone we need a cultural change and hopefully Frank can lead that. When he joined he banged on about the culture at Brentford being a team effort and one that takes time to build. He intimated its importance in interviews while there. The ENIC thread has been full for years with people rightly saying Levy prioritised finances and winning transfer deals over actually winning on the pitch. Maybe with him gone it can be achieved. Who knows, but I definitely know it will take longer than 3 months.