The 'plants feel pain too' smokescreen suggests, 'Since I can't prevent pain totally, I'm totally absolved from doing anything to prevent (or reduce) pain! '

以“植物也有痛感”为借口的人们又建议“既然我无法阻止所有的痛苦，我完全没必要阻止（或减少）痛苦的产生”。