I know this board has major issues understanding this. But Deadpool was a love story. Wade and Nessa's relationship was a huge reason why audiences connected to it. Take out the cancer, relationship and heavier dramatic scenes of torture and the film just doesn't work as well. It balances alot well even with the goofy insanity.
If films like Deadpool were so easy to get made, then Fox and other studios would have made it or films lake it 5 years ago. It was different, and looked at as a risk even with a PG-13. That wasn't cause it was a simple stupid R rated movie. It had heart, character, drama, action, romance, horror, comedy, broke rules, had charismatic leads and offered something new to audiences in terms of style in a maintstream comic film.