Politics doesn't work that way. Whether a person's chosen candidate won or lost an election, his/her right to criticize and demand transparency and accountability doesn't go away. His/her right to speak out remains.
This "move on kayo en" mindset is divisive. When you use it as an argument, you are saying that people have no say in political matters because their candidate lost. You're saying that their voices and their concerns aren't worth listening to because their candidate lost.
A community that values good governance, transparency, and accountability listens to both the winning side and the losing side. Brushing aside or trying to silence a person because he/she is on the losing side is narrow-thinking.