Hey man, when the Senior Minister of State says you just "need a very small space to have sex", you best believe that folks are gonna react wildly. According to Josephine Teo, sweet baby-making doesn't require young couples to get HDB flats early (when they can be hosted by their parents) — so there really should be no excuses for not contributing to the national population.
We don't know about her, but we prefer doing the dirty somewhere away from the ears and eyes of our relatives (unless that's your fetish, you sicko). In any case, the conversation shouldn't be about having adequate space to do the happy happy — it's an issue about having adequate space and environment to raise kids.