Being kind is inherent. Kindness never fade in people. Kindness can only mature to be realistic and sophisticated. The latter quality is important to prevent from being taken advantage of.
MRT passengers are kind. Forget about those who aren't. Focus on the positive people.
Most are willing to let go of their seats for needy passengers. Ladies who are moms themselves are more empathetic and they are frequently seen giving up their seats to pregnant/expectant moms (with the "I know how you feel" look).
Guys, who have got wives are willing to give up their seats to expectant moms. They are empathetic too.
If SMRT and SBS are willing to start a campaign to introduce "care bands" (or other identifiers) for MRT users, so that needy passengers will be able to identify who are willing to give up their seats, I believe there will be a lot of takers. These good Samaritans will be "beacon" for needy people. A beacon of care. A beacon that is contagiously good.
We have been exposed to the bad/ugliness of MRT passengers in Singapore, mostly thanks to Stomps, Blogs, and YouTube for the negative portrayal. What is lacking is to show to Singapore and the world that there are good, majority, but silent apples too in any society.