Why always punishing failed rolls?

Franz has a tendency to be extremely dichotomic on skill check rolls and it seems he always punishes rolls below 6 when critical fails aren't a real 5e rule. (Its just an extremley popular house rule). Maybe give franz an array for skill checks where failed rolls within a certain threshold makes minor progress but doesnt succeed. To reflect the sliding scale of actual game skill checks.

Examples are: if you roll a 10 on a dc11 perception check, the party almost ALWAYS gets ambushed, or they take damage because they stumble and fall or something ridiculous when the real response would be “You don'tnotice anything unusual or out of place.”

Failing a history check within the range of 2 or three will make a bookshelf fall on your character.

Failed rolls should not instantly result in punishment. Most of the time they should just be neutral responses.