Because there arent proper checks and balances.
So just like the corporate world and the us government the shitbags get in power and do whatever the hell they want with little to no repercussions.
The teamsters just went through that for years with that shitbag Hoffa jr. He just let the companies do pratically whatever they wanted.
Then you got stewards and shit who dont wanna do anything.
I didnt know any union reps/stewards until I went to managment.
Basically they only care about collecting dues and increasing their numbers.
They union doesn’t ‘demand’ anything beyond paying dues from its members so you’ve got tons of people who really think they can act however they want.
Complete lack of any sort of rules of conduct and no work ethic.
Dont know if it’s true or not, but I always assumed it was because the numbers get bigger left to right. Only 12 months, 30ish days, thousands of years.