The hypothesis after many years of working with, in and observing big companies is that many have toxic cultures. A lot of this also happens in small companies and upstarts... but the 20 reasons below are definitely prevelant (in our humble opinion) in today's big businesses: 

1} Politics. Politics politics. So many boards are people with big egos, differing styles and hidden agendas and all still trying to get to the top dog position. This often forms different camps (like in political parties), when the CEO goes, one person gets the nod and then all those aligned to him/ her move upwards or get the power. So many decisions are made not for the good of the company but for the politics and the 'moriarty art of war' chess match power plays going on....  

2} Uninspiring Leadership. The CEO or Board don't inspire. The Founder loses their oomph as they get further and further away from the doing and sharp end of why they started their company in the first place

3} Revolving doors at the top. With large companies changing CEOs (the average tenure in the top job in UK company is 4.8yrs) this leads to constantly changing direction. cycle of new person comes in wants to make their mark then leaves or gets ousted. Not surprising some of the best companies are the ones where the CEO has been there 15-20 years

4} It's not a level playing field. You get differences in ability. Some people rise in a company by just being in the right place at the right time/ managers move and they dont get exposed. Small companies there's no hiding so the wheat is sorted from the chaf pretty quickly

5} The leadership isnt walking the walk. They are talking a good game about company change but they arent demonstrating doing what they are saying

6} Play Safe. Not wanting to stand out challenge the status quo. Why put your ass on the line and risk speaking out....people become risk averse

7} Stepping Stone for careers. Get the big brand under the belt and move on in a few years to the job you really want. Means you go in, tread water and leave once its an acceptable amount of time to move on for your CV

8} Red Tape. Decision by committees, process, regulations, you just cant action any change quickly, the lack of progress for most trailblazers makes then unhappy  

9} Big companies often employ sh/t hot agencies but the person responsible for enabling and managing that agency has never worked agency side. This leads to an inability to get the most out of the agency which leads to ass covering on the brand side 

10} Supplier not partner. When you have every agency courting you and you can call a pitch with 13 agencies willing to take part, you often see agencies as just another supplier. When the big company treats its agency like just a supplier, the agency loses its inspiration, the work then suffers

11} Procurement. Built to leverage power and negotiate, rewarded on squeezing suppliers. Enough said....

12} Arse covering.  Everywhere 

13} Square peg round hole. Often Snr Management are moved around within the company. They are moved sideways (see point 1) and given a role they have no experience in, demoralising those they manage who are the experts and are reporting to an ineffective leader whilst they learn the basics of the role 

14} It is safe to say if you are in a big company you will be thrown under the bus by someone far more cut throat and 'get promoted or be seen

15} Employ 'Ds'. Companies get large they start as A list employees, soon they start hiring the odd B-level, they employ Cs... The As get disillusioned with working with Bs and Cs and soon enough you majority C and D-level

16} Often workers get an inflated sense of self as they are associated with that brand despite it not reflecting their ability   

17} You can throw money at the problem. Its easy to make. The safety net of knowing if you make a mistake you can throw money at the problem to dig yourself out of it. Makes you complacent. Smaller companies where every decision can be made once or there is only budget for one attempt keep you sharp

18} Pay grades and levels. Are you a B2? An E1? Its a minimum 3 years till you get to E level. Its pretty demoralising knowing your dream pay is 6 levels away and there is no way to fast track no matter how good your output or impact is

19} Many realise they are a tiny fish in a big pond and can't make real impact

20} Top down decisions made at Global arent flexible enough to be localised and so many at local level are having to action something that isnt relevant to their local market or local cultural nuances. And so they become disempowered and disillusioned