When I play chess with my friend I usually ask for his consent to beat him.
Then he soundly beats me and I am mad because he did not ask for my consent. Wait, bad example.
All kidding aside, times have changed. If you played wargames with your bearded wargame pals smoking camels in the basement some yesteryear, this contract or agreement would seem pretty absurd.
But culture and times change. Expectations differ. The player base has gotten younger and more sensitive to certain things. You market to your audience.
Though I do remember whining a fair bit when my DM cursed my dwarven fighter with lyncanthropy of some odd sort. I would turn into a moon dog and did not want to roleplay it. Maybe I should have had a contract with him

probably would have been better than my whining.
Now? I would roll with it. But people have different preferences.