It seems it's a HDB thing to not want to leave shoes outside because, among other things, people might steal them:
A: So sad.. My flat shoes at my corridor stole when I was about leaving home for work. Sighs
B: I'm not very civilized... So are my neighbours 😂 we trust each other
C: I had my old shoes stolen about 18 years ago. From that time onwards, I never leave my shoes or slippers outside.
D: The rain could make them wet
E: the more expensive shoes u should keep inside when its still new
but then i bought a new pair of sandals for $38
it got stolen that night lol
To be fair condos restrict access.
Only DBSS hdb have some type of restriction for access
F: I just don’t like leaving my shoes outside because I feel it’s so messy. Case in point we want to buy this neighbour of ours a shitty shoe rack because they just leave their shoes all over the floor outside their house
G: Why tempt people
H: Not just rain, the workers that wash the corridor will just spray everything
They try to remove stuff but if there is too much, it's also difficult for them to do their work
I: I always thought this was an urban legend
J: It's not. I had something of mine stolen before.
K: Had several slippers stolen before.
L: If you leave your shit outside, expect it to get stolen.
it happens in condo also. My neighbor sandals got stolen suspected delivery guy.
I: Some people in HDB flats have shoe racks in the hallway outside their home
M: My family had a few pairs of shoes thrown down the stairs by someone for fun. Not very fun for us. Especially when we could only find one side of the shoe.