As somebody who did it twice I learned there are usually 3 reasons why people do it:

• they are assholes
• the game was really disappointing inclusive the time window to finish / price for the game
• they want to see if they fan speed run zhr game and refund it. (For example portal 2)

Paddle Paddle Paddle, is a fun game and does not deserve that treatment. It also has a fun replay value with different friends :D