This a litany of systematic mistakes coupled with some individual pilot errors under high stress load. When the safety chain gets compromised this many times in an organization, an error chain develops and then nobody can really stop it at the final level (ie. pilot). The genesis of most of it is money-driven behavior by most companies to farm anything possible out to the lowest bidder. I see this all the time, and what it does is remove the correct eyes from the job and put someone who is not actually responsible/knowledgeable there. For example, the ramp where I fly snow is supposedly removed by a contractor, but the contractor does not know what really needs to be done since they are not in the flying business, they are excavators mainly, but since they are supposedly qualified to do the job nobody higher up watches very closely to see what they are actually doing. They do the minimum to get the paycheck because that's all that's in it for them. So when the pilots go to their plane, there's two feet of snow drift around it and not as much as a vague plan for removing it by anyone. This is an example of systematic organizational error chain. Now the pilot has to remove a ton of snow to maintain proper safety, which is not in their job description.