During national service, men identified as gay (302) or even effeminate (30-B) are sidelined into non-sensitive roles. However, they are now allowed to remain on base overnight and take on night duties.
Since around 2003, the Gahment has allowed openly gay men to take "sensitive" roles in the civil service.
Quite the same kind of "don't ask, don't tell" that happened in the UK and her other colonies.
Being gay isn't illegal in Singapore - "gross indecency" between men is, "obscene acts" in public are illegal, or you could get done under section 19 for other immoral purposes. The latter two apply to anyone in Singapore, not just gay men.
The gay bars and nightclubs have largely been left alone by the police in recent years.
Some Asian cultures are more touchy-feely than Western cultures. Witness a gang of Bangladeshi builders slouched across each other during break time...you would get beaten up in the UK for man on man contact like that! Maybe this is the difference you perceive between asian and western couples?
Regarding Pink Dot...that wasn't a gay gathering. It was a gathering of people in support of "Freedom To Love". There was never any mention of it being a gay event.

Hence the application to have the gathering at Speaker's Corner was successful...locals playing the Gahment at their own game...