Your skin is too thin. Of course there are a lot of good English speakers here (Singaporean ones as well). Most of the Singaporeans who when overseas for the uni educations actually have learned to speak proper (or better) English while overseas and immersed in those communities. However, as of late, it has been noted that Singaporeans don't tend to mix at the Uni level while overseas, but tend to stay within their own little clique - this is not good and borders on xenophobic and it also inhibits their English from improving.
It's just like the "kiasu" mentality. This country is known as being "extremely" kiasu. So much so that's it's considered part of the description of being a Singaporean. Now. How did they get that "trait"? Are you going to say ALL Singaporeans are like that? Of course not. BUT. A larger percentage of Singaporeans exhibit this trait than others in other countries do. Therefore, while it may well not be the majority, the percentages are much, much higher than the norms. Therefore the 'trait' is stamped on the citizen. This bastard of a language, singlish, is much the same. How long ago did you do your primary schooling here? Have you, as an adult (I'm assuming you are one) ever gone back to listen to an English class being taught in primary schools here? Have you ever taken a good look at written English exams/papers here since you left school? You would be horrified. Yeah, the mechanics of Science and Math are irrefutable so Singaporeans excel there. But English? Sorry, I still have to disagree.
And yes, the question I've just asked you, I've done myself. Both of my kKids went through the local system from Primary to O's to tertiary. One speaks proper English all the time and has to make an effort to speak singlish. The other, well, lets just say he went to a neighbourhood school where the first didn't. He can code switch anytime he wants as well, but he's more in tune with singlish but due to hearing proper English at home from both parents he can speak proper English any time. (one parent is a Singaporean - but taught by native English speakers back in those days of the British Occupation). My kids are fluent in English, singlish, Mandarin and understand Tamil but don't speak the language out of preference.
SOME PEOPLE TRY TO TURN BACK THEIR ODOMETERS. NOT ME. I WANT PEOPLE TO KNOW WHY I LOOK THIS WAY. I'VE TRAVELED A LONG WAY, AND SOME OF THE ROADS WEREN'T PAVED. ~ Will Rogers