I think expats complain about this too much.
In my experience excellent service is definitely possible. Go to the right restaurants and you will be served with just the right amount of attention. Personally, when I'm dining I want unobtrusive but aware staff, and many restaurants deliver on this.
As for warm, highly personal service, like you can get in places like Australia...I've not seen it. But I don't fault the locals: often there are genuine communication difficulties, and these can be one-sided. Many of us have been listening to Singaporean cocktalk for years and understand it well, but for them it can be rare to speak to a foreigner...and we all have different accents, too!
One mistake some of my friends make is to compare Singapore service with that found in more expensive places. Sure, you can buy a top quality croissant and get a warm smile in London, but it costs about three times as much.