Excuse me sir, but this is not a crowded station, so no need at that time to deploy crowd control measures. I am sure you will be able to upload pictures of unruly situations in Third World countries like India or China, but the standard of care expected in SG are much higher since their MiniStars are paid OUT OF THIS WORLD salaries!
I'm showing examples of underground systems that have existed for more than 100 years without barriers and which have even bigger crowds than the MRT.
Unless Singaporeans are a special breed that have no control over their actions, I do not see why Singapore needs measures that first world western nations have never found necessary.
If you put barriers at train stations, you might as well barricade all the roads. Far more people are maimed and injured on the road network.