I've been to Singapore Sam's many, many times - at times arriving with drunken people (in my party or others' parties) after last call. Some of these inebriated people are the ones who mar the image of this business, making it a bad experience for others and for the staff.
I have never served tables or worked in the service industry but can imagine it to be specially difficult to perform when tending to 'drunks'.
Prices are high at night - I'm not sure about lunch time, never been there at that time.
Yes, this is fast food quality food but they've got the best GINGER BEEF in town!