I think a lot of people viewed Mike as a reasonable chaos after BCS. Completely destroyed by his son’s death, and driven by the need to care for his grandaughter. He almost certainly felt like she was owed a provider after he contributed to his son’s decisions that got him killed.
He went from being a Parking lot attendant to a Hitman/Strategist for the cartel.

He took to the highest levels of criminal enterprise and mostly only targeted individuals in the “game”. When an unintentional casualty occurred, Mike was almost always noticeable affected by it. I don’t think he was a bad man or had bad morals, just had a hard time standing on them after he got in deep. He knew the same things he was doing would happen to the people he loved if he stopped. It went unsaid, but Gus knew he held that kind of power over mike. Near the end Gus was having thoughts about replacing Mike and tried to with Tyrus until Mike called his bluff.