$x$ is superior to Training Program $Y.$

Which of the following statements, if true, would most seriously weaken the above argument?

Training Program $Y$ is more fun than Training Program $x,$ according to those who took both.

The developers of Training Program X are not well liked by their coworkers.

A vocal minority believe that people skills are not nearly as important as technical skills.

After six months, people who took Training Program $x$ had people skills similar to those who took Training Program $Y.$

After one year, people who took Training Program Y had better people skills than people who took Training Program X $.$